tag:theconversation.com,2011:/fr/topics/lava-12166/articlesLava – The Conversation2024-01-17T13:37:30Ztag:theconversation.com,2011:article/2212832024-01-17T13:37:30Z2024-01-17T13:37:30ZIceland battles a lava flow: Countries have built barriers and tried explosives in the past, but it’s hard to stop molten rock<figure><img src="https://images.theconversation.com/files/569684/original/file-20240116-25-6bp82a.jpg?ixlib=rb-1.1.0&rect=158%2C22%2C1637%2C996&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lava flows from a fissure near Grindavik, Iceland, on Jan. 14, 2024. </span> <span class="attribution"><a class="source" href="https://www.facebook.com/Almannavarnir/">Iceland Department of Civil Protection</a></span></figcaption></figure><p>Fountains of lava erupted from the Sundhnúkur volcanic system in southwest Iceland on Jan. 14, 2024. As the <a href="https://www.youtube.com/watch?v=Bqudj0x0POA">world watched on webcams and social media</a>, lava flows cut off roads and bubbled from a new fissure that invaded the outskirts of the coastal town of Grindavík, burning down at least three houses in their path.</p>
<p>Nearby, construction vehicles that had been working for weeks to <a href="https://www.constructionbriefing.com/news/the-construction-teams-working-to-hold-back-a-volcano/8033447.article">build large earthen dams and berms</a> in an attempt to divert the lava’s flow had to pull back.</p>
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<a href="https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The glow from lava lights up the sky with a town nearby in front of it." src="https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569683/original/file-20240116-19-avqjr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The lava flow on Jan. 14, 2024, with Grindavík in the foreground.</span>
<span class="attribution"><a class="source" href="https://www.facebook.com/Almannavarnir/">Iceland Department of Civil Protection</a></span>
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<p>Humans have tried many ways to stop lava in the past, from attempting to freeze it in place by cooling it with sea water, to using explosives to disrupt its supply, to building earthen barriers. </p>
<p>It’s too soon to say if Iceland’s earthworks will succeed in saving Grindavík, a town of <a href="https://guidetoiceland.is/travel-iceland/drive/grindavik">about 3,500 residents</a>, and a nearby <a href="https://www.visir.is/g/20232488946d/um-thrjatiu-vorubilar-notadir-til-ad-saekja-efni-ur-stapafelli">geothermal power plant</a>. As <a href="https://scholar.google.com/citations?user=9NUvHX4AAAAJ&hl=en">a volcanologist</a>, I follow these methods. The most successful attempts to stop or reroute lava have involved diversions like Iceland’s. </p>
<h2>Why lava is so hard to stop</h2>
<p>Lava is a <a href="https://www.usgs.gov/programs/VHP/lava-flows-destroy-everything-their-path">sluggish, viscous fluid</a> that behaves somewhat like tar. It is subject to gravity, so like other fluids, it will flow downslope along a path of steepest descent.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/C9etIuS5hBg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Images of Grindavik and the barrier being built to try to protect the town and geothermal power plant. Insider News.</span></figcaption>
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<p>With the temperature of its molten rock often <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-how-do-lava-flows-cool-and-how-long-does-it-take">well above 2,000 degrees Fahrenheit</a> (1,000 Celsius), not much can stand in its way.</p>
<h2>Freezing lava in its tracks</h2>
<p>In 1973, Icelanders attempted the <a href="https://pubs.usgs.gov/of/1997/of97-724/methods.html">most famous “lava freezing” experiment</a>. They used water hoses from a flotilla of small boats and fishing vessels to protect the small island community of Heimaey from the Eldfell volcano’s lava.</p>
<p>The lava flows were threatening to close off the harbor, which is critical to the region’s fishing industry and a lifeline to the Icelandic mainland. The eruption ended before the success of the strategy could be properly evaluated, but the harbor survived.</p>
<h2>Fighting lava with explosives</h2>
<p>Hawaiians used <a href="https://doi.org/10.1007/BF02600367">explosives dropped from planes in 1935 and 1942</a> to try to disrupt lava flows from Mauna Loa volcano that were threatening the town of Hilo on the Big Island. </p>
<p>The idea was to disrupt the channels or lava tubes in the volcano that were supplying lava to the surface. Neither attempt was successful. The explosions created new channels, but the newly formed lava flows soon <a href="https://pubs.usgs.gov/pp/1801/downloads/pp1801_Chap10_Tilling.pdf">rejoined the original lava channel</a>.</p>
<h2>Lava barriers and diversions</h2>
<p>Most recent efforts have focused instead on a third strategy: building dams or ditches in an attempt to divert the lava’s flow toward a different path of steepest descent, into a different “lavashed,” a <a href="https://oceanservice.noaa.gov/facts/watershed.html">concept similar to a watershed</a> but where lava would naturally flow.</p>
<p>Results have been mixed, but diversion can be successful if the lava flow can be clearly diverted into a distinct area where lava would naturally flow – without threatening a different community in the process.</p>
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<a href="https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An earthen berm with black lava along the one side of it. The lava broke through along a highway." src="https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569688/original/file-20240116-17-hi8it9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Lava breached one section of the earthen barrier near Grindavík after the Jan. 14, 2024, eruption, but it largely followed the effort to divert it.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/drone-is-capturing-the-town-of-grindavik-during-the-news-photo/1928389535?adppopup=true">NurPhoto via Getty Images</a></span>
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<p>Many attempts to divert lava have failed, however. Barriers built in Italy to <a href="https://doi.org/10.1016/0377-0273(93)90048-V">stop Mt. Etna’s lava flows</a> in 1992 slowed the flow, but the <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-what-does-it-take-successfully-divert-a-lava-flow">lava eventually overtopped each one</a>.</p>
<h2>Iceland’s diversion efforts</h2>
<p>Icelandic authorities evacuated Grindavík’s residents in November 2023 <a href="https://theconversation.com/volcanic-iceland-is-rumbling-again-as-magma-rises-a-geologist-explains-eruptions-in-the-land-of-fire-and-ice-217671">after swarms of earthquakes</a> indicated a reactivation of the nearby volcanic system.</p>
<p>Shortly afterward, construction began on protective barriers for the town and some nearby critical infrastructure – notably, the Svartsengi geothermal power station. Construction had to be put on hold in mid-December, when a <a href="https://theconversation.com/volcanic-eruption-lights-up-iceland-after-weeks-of-earthquake-warnings-a-geologist-explains-whats-happening-220193">first volcanic eruption</a> occurred about 2.5 miles northeast of Grindavík, but work resumed in January. Work was still underway when magma reached the surface again on Jan. 14.</p>
<p>Diverting lava in this region is difficult, in part because the land around Grindavík is relatively flat. That makes it harder to identify a clear alternative path of steepest descent for redirecting the lava. </p>
<p><a href="https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night">Icelandic officials reported</a> on Jan. 15 that most of the lava from the main fissure had flowed along the outside the barrier, however a <a href="https://guidetoiceland.imgix.net/1322526/x/0/grindavik-2.jpg">new fissure</a> had also opened inside the perimeter, sending lava into a neighborhood. Unfortunately, that implies that Grindavík remains at risk.</p><img src="https://counter.theconversation.com/content/221283/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Loÿc Vanderkluysen receives funding from the National Science Foundation</span></em></p>Iceland, Hawaii and Italy have all tried to control lava to save cities in the past. A volcanologist explains the methods.Loÿc Vanderkluysen, Associate Professor of Earth Science, Drexel UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2195462024-01-02T16:49:57Z2024-01-02T16:49:57ZPrivatised Moon landings: the two US missions set to open a new era of commercial lunar exploration<figure><img src="https://images.theconversation.com/files/566549/original/file-20231219-23-qde9s6.jpeg?ixlib=rb-1.1.0&rect=0%2C2%2C1839%2C984&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/10836">Photograph: Nasa (Goddard Space Flight Center)</a></span></figcaption></figure><p>Two commercial spacecraft are scheduled to launch to the Moon early in 2024 under a Nasa initiative called the Commercial Lunar Payload Service <a href="https://www.nasa.gov/commercial-lunar-payload-services/">CLPS</a>. This programme is intended to kickstart a commercial transportation service that can deliver Nasa experiments and other payloads to the lunar surface.</p>
<p>If successful, these missions will represent the first landings on the Moon by spacecraft designed and flown by private companies. They could potentially open up a new era of commercial lunar exploration and science. </p>
<p>CLPS was inaugurated by Nasa in 2018. An initial pool of nine companies received an invitation to join the programme. They included <a href="https://www.astrobotic.com/">Astrobotic</a> and <a href="https://www.intuitivemachines.com/">Intuitive Machines</a>, the two companies behind these missions. Both missions expect to land within a week after lift-off.</p>
<p>The first launch, and the first Nasa flight of 2024, is the Peregrine lunar lander, built by Pittsburgh-based Astrobotic. It is scheduled to launch at the earliest on January 8. Broadly speaking, the lander is a box the size of a medium-sized garden shed containing several separate experiments. </p>
<p>These include a set of mirrors called a laser retro-reflector array, used for accurate positioning of the lander from orbit. There are also a number of spectrometers – instruments that separate and measure the distinct colours found in light. These will measure radiation on the lunar surface and look for signatures of water in lunar soil.</p>
<p>One of them, the <a href="https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=PEREGRN-1-02">Neutron Spectrometer System</a>, will look for hydrogen-containing materials on the surface, which can indicate the presence of water below ground. This water could one day be used by human explorers.</p>
<figure class="align-center ">
<img alt="Astrobotic Peregrine lander." src="https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C1917%2C1279&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566548/original/file-20231219-19-i3ffem.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Astrobotic’s Peregrine lander will touch down near the Gruithuisen Domes.</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/details/KSC-20231114-PH-ILW01_0100">Isaac Watson/Nasa</a></span>
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<p>There are two principle sources of dangerous radiation for humans in space. One is the Sun, which unleashes electrons, protons and heavier ions that are accelerated to a significant fraction of the speed of light. </p>
<p>These solar energetic particle events (SEPs) are more likely to occur during the Sun’s peak of activity (solar maximum), which occurs every 11 years. However, that does not mean there is a respite during the solar minimum.</p>
<p>The other source of harmful radiation is galactic cosmic rays (GCRs). These energetic particles originate outside the Solar System, probably in explosive phenomena such as exploding stars (supernovas).</p>
<p>During periods of lower solar activity (including the solar minimum), the Sun’s magnetic field, which extends throughout the Solar System, weakens. This enables <a href="https://www.researchgate.net/figure/Solar-cycle-%20modulation-and-anti-correlation-of-GCR-flux-with-solar-activity-Shown-are_fig6_257343697">more GCRs</a> to reach us instead. </p>
<p>Another spectrometer on Peregrine will measure both SEPs and GCRs on the Moon. This is important for examining how dangerous the radiation environment at the lunar surface will be for future human explorers.</p>
<h2>Polar landing</h2>
<p>The second spacecraft to launch early in 2024 is the <a href="https://www.intuitivemachines.com/im-1">Nova-C lander</a>. It is designed by Houston-based Intuitive Machines and has a similar volume to Peregrine, but in the shape of a tall, hexagonal cylinder. It will carry several instruments including its own laser retro-reflector array. Nova-C is currently scheduled to launch in mid-February.</p>
<p>Other instruments include a suite of cameras for producing a 3D image of Nova-C’s landing site. This will allow scientists to estimate how much material is blown away by the landing rocket’s exhaust plume during the descent. Potentially, any material blown away can be imaged to get an idea of the composition of surface material. </p>
<figure class="align-center ">
<img alt="Nova-C lander." src="https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566583/original/file-20231219-23-2hpa5p.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A model of the Nova-C lander.</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/details/NHQ201905310022">Nasa (Goddard Space Flight Center)</a></span>
</figcaption>
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<p>The “radio observations of the lunar surface photo-electron sheath” (<a href="https://arxiv.org/pdf/2102.02331.pdf">Rolses</a>) instrument is designed to measure how the extremely tenuous lunar atmosphere and the Moon’s surface dust environment affect radio waves. </p>
<p>The behaviour of electrically charged dust particles on the Moon is a technical challenge which future explorers will need to deal with, as the abrasive particles can attach themselves to surfaces and mechanical devices and potentially cause harm if <a href="https://www.wired.com/story/the-%20next-big-challenge-for-lunar-astronauts-moon-dust/">inhaled</a> by astronauts.</p>
<p>A privately built experiment onboard Nova-C is the International Lunar Observatory <a href="https://iloa.org/ilo-x-precursor/">ILO-X</a>, which will aim to capture some of the first images of the Milky Way galaxy from the Moon’s surface. This would demonstrate the concept of lunar-based astronomy.</p>
<h2>Landing locations</h2>
<p>Peregrine’s landing site is a bay on the west side of Mare Imbrium, known as Sinus Viscositatis (Bay of Stickiness). Here, two volcanic mountains called the <a href="https://moon.nasa.gov/resources/482/a-lunar-%20mystery-the-gruithuisen-domes/">Gruithuisen Domes</a> are made of a different material to the surrounding plains. </p>
<p>The plains are a form of basalt, while the domes are composed of silica. Both are volcanic in origin, but one appears to have been formed by lava with a viscosity of mango chutney (the silica), and the other by runnier lava (the basalt). </p>
<figure class="align-center ">
<img alt="Gruithuisen Domes" src="https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566614/original/file-20231219-29-7x7oaq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Gruithuisen Domes appear to have been formed by silica lavas.</span>
<span class="attribution"><a class="source" href="https://moon.nasa.gov/resources/482/a-lunar-mystery-the-gruithuisen-domes/">Nasa (GSFC)/Arizona State University</a></span>
</figcaption>
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<p>On Earth, silica lavas typically require the presence both of water and plate tectonics. However, plate tectonics are not known to be present on the Moon, and neither is water in the quantities necessary for silica lavas. The Gruithuisen Domes thus present a geological enigma which Peregrine could go some way to resolving.</p>
<p>The landing location for Nova-C is Malapert A crater – which is of particular interest for lunar exploration, as it lies close to the Moon’s south pole. The surrounding mountains permanently shield this depression from sunlight, leaving it in constant darkness. </p>
<p>Consequently, it is one of the coldest locations in the Solar System and, given the lack of sunlight, a place where water ice delivered by comets hitting the surface over the aeons could remain stable. Future human explorers could use it for life support and making rocket fuel.</p>
<figure class="align-center ">
<img alt="Lunar south pole." src="https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566615/original/file-20231219-27-888tuc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An image of the Moon’s South Pole showing the Malapert crater (foreground).</span>
<span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/5127">Nasa's Scientific Visualization Studio</a></span>
</figcaption>
</figure>
<p>There are additional payloads on both spacecraft from private investors. Peregrine contains the “DHL Spacebox”, which will carry personal items from paying customers, while Nova-C contains “The Humanity Hall of Fame” – a list of names to be sent to the Moon for posterity. Such payloads can generate additional funding for the launch companies.</p>
<p>Several other companies are due to launch their first payloads to the Moon in the next couple of years. With greater input from private companies – assuming the these first few missions succeed – we may soon witness a new era in lunar exploration.</p><img src="https://counter.theconversation.com/content/219546/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Peregrine and Nova-C landers are due to carry out valuable science at two diverse lunar locations.Gareth Dorrian, Post Doctoral Research Fellow in Space Science, University of BirminghamIan Whittaker, Senior Lecturer in Physics, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2201932023-12-19T21:59:56Z2023-12-19T21:59:56ZVolcanic eruption lights up Iceland after weeks of earthquake warnings − a geologist explains what’s happening<p>Lava erupted through a fissure in Iceland’s Reykjanes Peninsula on Dec. 18, 2023, shooting <a href="https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night">almost 100 feet (30 meters)</a> in the air in its early hours.</p>
<p>Icelanders had been anticipating an eruption in the area for weeks, ever since a <a href="https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night">swarm of thousands of small earthquakes</a> began on Oct. 23 northeast of the fishing town of Grindavík, signaling volcanic activity below. </p>
<p>In the days that followed those first rumblings, a series of small rifts opened under the town, breaking streets, rupturing utility lines and tilting houses. GPS stations detected the <a href="https://en.vedur.is/about-imo/news/earthquake-activity-in-fagradalsfjall-area">ground sinking and rising</a> over a large area.</p>
<p>Geologists from the <a href="https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night">Icelandic Met Office</a> interpreted the events as evidence that a basalt dike – pressurized magma that forces its way into a fracture – had intruded under Grindavík. The activity there had tapered off by early December, but 2.5 miles (4 kilometers) north of town, the ground under the <a href="https://www.verkis.com/projects/energy-production/geothermal-energy/nr/936">Svartsengi</a> geothermal power plant was moving.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map shows the location of the fissure." src="https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566683/original/file-20231219-19-6waspp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The location of the fissure where magma erupted starting Dec. 18, 2023, a few miles from the town of Grindavík and just east of Svartsengi power plant and ajacent Blue Lagoon thermal spa.</span>
<span class="attribution"><a class="source" href="https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night">Icelandic Met Office</a></span>
</figcaption>
</figure>
<p>The ground had dropped 10 inches (25 centimeters) as the basalt dike filled, but then it began to rise in a broad dome, indicating that magma was reinflating and repressurizing the magma chamber. The result was the nearby eruption on Dec. 18.</p>
<p>If the fissure continues to propagate to the south, or if a large volume of lava erupts, the evacuated town of Grindavík, with a population of around 3,500, may be in danger. The lava could also spill to the northwest toward the power plant, although the utility built rock walls to try to divert lava flows.</p>
<figure class="align-center ">
<img alt="An aerial photo shows the lights of Grindavík and glow of the eruption very nearby." src="https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=498&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=498&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566707/original/file-20231219-25-zfbj7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=498&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The evacuated town of Grindavík and a nearby geothermal power plant are still at risk.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-evacuated-icelandic-town-of-grindavik-is-seen-as-smoke-news-photo/1860420658?adppopup=true">Viken Kantarci/AFP via Getty Images</a></span>
</figcaption>
</figure>
<p>Iceland is known as “the land of fire and ice” for a reason. Its residents have learned over centuries to live with its overactive geology.</p>
<p>The reason for Iceland’s volcanism has two parts: One has to do with what geologists unimaginatively <a href="https://oceanexplorer.noaa.gov/facts/volcanic-hotspot.html">call a hot spot</a>, and the other involves giant tectonic plates that are pulling apart beneath the island. As <a href="https://scholar.google.com/citations?user=r8FqGBEAAAAJ&hl=en">a geologist</a>, I study both.</p>
<h2>Life on the edge of two tectonic plates</h2>
<p>When <a href="https://www.iris.edu/hq/inclass/animation/plate_tectonic_theorya_brief_history">plate tectonic theory</a> was emerging in the 1960s, geologists realized that many volcanoes are located in zones where tectonic plates meet. Tectonic plates are gigantic chunks of Earth’s rigid outer layer that carry both continents and oceans and are constantly in motion. They <a href="https://www.usgs.gov/media/images/tectonic-plates-earth">cover the planet</a> like large pieces of a spherical jigsaw puzzle.</p>
<p>Many of these volcanoes are in subduction zones, like the Pacific’s <a href="https://education.nationalgeographic.org/resource/plate-tectonics-ring-fire/">Ring of Fire</a>, where thinner oceanic plates slowly sink into <a href="https://education.nationalgeographic.org/resource/mantle/">Earth’s mantle</a>. These are the postcard stratovolcanoes like Mount Fuji, in Japan, or Mount Rainier, outside of Seattle. Because of their high gas content, they tend to erupt catastrophically, shooting ash high into the atmosphere with the energy of nuclear bombs, as <a href="https://www.usgs.gov/volcanoes/mount-st.-helens/science/1980-cataclysmic-eruption">Mount St. Helens did in 1980</a>.</p>
<p>A second, typically quieter kind of volcano forms <a href="https://oceanexplorer.noaa.gov/facts/mid-ocean-ridge.html">where plates pull apart</a>.</p>
<p>The volcanic activity near Grindavík is directly related to this kind of plate tectonic motion. The mid-Atlantic ridge between the Eurasian and North American plates cuts right through that part of the island.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map shows where the earthquakes are taking place in a southwest peninsula and where the tectonic plates meet." src="https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=780&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=780&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=780&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=980&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=980&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559688/original/file-20231115-22-mdyae8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=980&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Iceland sits atop the meeting of two tectonic plates, the North American to the west and Eurasian to the east, indicated by the red line crossing the island. The maps show the earthquake swarms on Nov. 12-14, 2023.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-infographic-titled-iceland-prepares-for-volcanic-news-photo/1782148842?adppopup=true">Yasin Demirci/Anadolu via Getty Images</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map shows details of midocean ridges looking like seams on a baseball as they wind through the major oceans." src="https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=330&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=330&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=330&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=415&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=415&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559732/original/file-20231115-27-7uf0ky.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=415&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In the 1950s, cartographer Marie Tharp used echo soundings gathered by ships to develop the first map showing the ocean floor in detail. It clearly revealed the mid-ocean ridges. This hand-painted version of her map includes annotations showing hot spot tracks related to movement of the plates.</span>
<span class="attribution"><a class="source" href="https://www.loc.gov/">Heinrich C. Berann via Library of Congress; annotations by Jaime Toro</a></span>
</figcaption>
</figure>
<p>In fact, at <a href="https://guidetoiceland.is/connect-with-locals/jorunnsg/ingvellir-national-park">Thingvellir National Park</a> you can literally walk between the two tectonic plates. You can see the topographic scars of the rift in the long, linear valleys that extend to the northeast from Grindavík. They align with the swarms of earthquakes, the <a href="https://en.vedur.is/about-imo/news/bigimg/4511?ListID=0">ground deformation</a>, and the fissure eruption of 2023.</p>
<p>Where plates pull away from each other, the underlying mantle rises toward the surface to fill the gap, carrying its heat with it and moving into an area of lower pressure. Those <a href="https://www.e-education.psu.edu/rocco/node/1988">two processes</a> cause melting at depth and volcanic activity at the surface.</p>
<p>This is the <a href="https://en.wikipedia.org/wiki/Sheeted_dyke_complex">same process that creates new oceanic crust</a> underwater at mid-ocean ridges. After the magma solidifies as basalt rock, it will look like vertical walls intruded into the surrounding area.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The uplift is in a large area that includes a nearby power plant and the Blue Lagoon thermal spa." src="https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=552&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=552&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=552&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=694&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=694&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566733/original/file-20231219-19-4i4dgz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=694&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A map shows the uplift of the ground (bright red) north of Grindavík prior to the Dec. 18, 2023, eruption, as well as the extent of the new lava flow (black).</span>
<span class="attribution"><a class="source" href="https://en.vedur.is/">Icelandic Met Office</a></span>
</figcaption>
</figure>
<h2>Sitting on a hot spot</h2>
<p>In Iceland, the large volcanoes in the interior also <a href="https://doi.org/10.1016/j.epsl.2013.02.022">appear to be over a mantle plume</a>, <a href="https://theconversation.com/where-mauna-loas-lava-is-coming-from-and-why-hawaiis-volcanoes-are-different-from-most-195633">similar to Hawaii</a>.</p>
<p>This kind of volcano typically erupts basalt lava, which melts at very high temperature and tends to flow easily. Eruptions are generally not explosive because the runny lava allows gases to escape. </p>
<p>Exactly what causes hot material to rise at hot spots is still debated, but the most commonly accepted idea is that they are caused by plumes of super-heated rock that originate at the transition <a href="https://doi.org/10.1126/science.349.6252.1032">between Earth’s metallic core and rocky mantle</a>. Hot spots are a mechanism for the Earth to give off some of its <a href="https://www.sciencealert.com/earth-s-insides-are-cooling-faster-than-we-thought-and-it-will-mess-things-up">internal heat</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Hl1gfV-TdU0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How hot spots develop. Video by Volcano Museum.</span></figcaption>
</figure>
<p>Typically, fissure eruptions are not explosive. However, when lava that is 1,800 degrees Fahrenheit (about 1,000 degrees Celsius) hits water, the flash to steam can cause explosions that can scatter ash over a larger area. </p>
<h2>A silver lining of Iceland’s volcanoes</h2>
<p>Living in an active volcanic area has some advantages, particularly for energy.</p>
<p>Iceland derives 30% of its electricity from geothermal sources that use underground heat to drive turbines and produce power. It’s almost like a controlled version of a lava flow hitting the sea, and it helps make Iceland <a href="https://www.volts.wtf/p/whats-the-deal-with-iceland#details">one of the cleanest economies on earth</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="People sit in an eggshell-blue lake surrounded by black lava rocks. Steam rises in the background." src="https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=758&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=758&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=758&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=953&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=953&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559465/original/file-20231114-21-f3fk7c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=953&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Iceland has a lot of natural hot springs, but its Blue Lagoon has an unusual origin linked to geothermal energy.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/people-swimming-on-hot-spring-near-mountain-during-daytime-jTeQavJjBDs">Photo by Jeff Sheldon on Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The <a href="https://www.verkis.com/projects/energy-production/geothermal-energy/nr/936">Svartsengi</a> hydrothermal plant uses the underground heat from the same magma chamber that is now erupting to provide hot water for several thousand homes, plus 75 megawatts of electricity.</p>
<p>That power plant is also part of the reason the <a href="https://www.bluelagoon.com/">Blue Lagoon</a> is so popular. When the power plant was built in 1976, the plan was to discharge its still hot wastewater into an adjacent low area, expecting that it would seep into the ground. However, the geothermal water was loaded with dissolved silica, which became solid minerals when the water cooled, creating an impermeable layer. A small lake began to form.</p>
<p>Because of its high silica content, the water in this lake is a spectacular blue color that inspired the creation of the geothermal spa. The Blue Lagoon is one of the top tourist attractions in the country.</p>
<p>Now the Blue Lagoon is at risk: Sometimes the volcano gives, sometimes it takes away.</p>
<p><em><a href="https://theconversation.com/pourquoi-leruption-volcanique-en-islande-na-rien-dune-surprise-les-explications-dun-geologue-220292">Lire en français</a></em></p>
<p><em>This is an updated version of an <a href="https://theconversation.com/volcanic-iceland-is-rumbling-again-as-magma-rises-a-geologist-explains-eruptions-in-the-land-of-fire-and-ice-217671">article published Nov. 15, 2023</a>.</em></p><img src="https://counter.theconversation.com/content/220193/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaime Toro works for West Virginia University. In the past, he has received funding from NSF, USGS and DOE.
</span></em></p>Iceland is known as ‘the land of fire and ice’ for a reason.Jaime Toro, Professor of Geology, West Virginia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2069772023-07-13T12:38:33Z2023-07-13T12:38:33ZLiving near the fire – 500 million people worldwide have active volcanoes as neighbors<figure><img src="https://images.theconversation.com/files/536136/original/file-20230706-25-u2xrop.jpg?ixlib=rb-1.1.0&rect=11%2C0%2C3778%2C2506&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Indonesia's Mount Merapi spews lava during an eruption on May 23, 2023. Over 250,000 people live nearby.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/indonesias-mount-merapi-one-of-the-worlds-most-active-news-photo/1257370107">DEVI RAHMAN/AFP via Getty Image</a></span></figcaption></figure><p>The thought of living near an active volcano probably sounds like an unimaginable risk to you – and rightly so. An active volcano is never safe and can turn a <a href="https://www.usgs.gov/volcanoes/mount-st.-helens/1980-cataclysmic-eruption">forested hillside into a lifeless wasteland in a matter of seconds</a>. From <a href="https://www.usgs.gov/programs/VHP/pyroclastic-flows-move-fast-and-destroy-everything-their-path">molten avalanches of rock</a> to <a href="https://volcanoes.usgs.gov/volcanic_ash/mount_st_helens_health.html">razor-sharp lung-shredding ash</a>, volcanoes threaten people’s lives and property. </p>
<p>Yet <a href="https://www.preventionweb.net/news/newsletter-xviii-jrc-study-assesses-global-human-population-living-proximity-active-volcanoes">500 million people</a> worldwide live and work under the shadow of active volcanoes. As a geologist who’s studied many volcanoes over the years, I’ve come to realize it’s naïve to ask, “Why don’t these people just move to less risky places?”</p>
<p>Their motivations range widely. For some, strong cultural beliefs and traditions keep them in place. For others, volcanoes offer significant economic opportunity. For the most vulnerable, poverty traps them in dangerous locations. </p>
<p>Whatever the reason, many people’s lives and welfare are so intimately linked with a volcano, moving elsewhere is unthinkable. </p>
<h2>Centers of identity</h2>
<p>Numerous cultures and Indigenous peoples <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-strong-ties-between-volcanoes-and-religion">revere volcanoes</a> as places of worship, ritual and tradition that are celebrated for their power over fertility, life and sustenance. </p>
<p><a href="https://www.nationalgeographic.com/travel/article/climbing-mount-fuji">For a number of religious traditions</a>, <a href="https://www.worldhistory.org/Mount_Fuji/">Mount Fuji</a> in Japan is a place where ancestral spirits congregate. It has been a <a href="https://www.taylorfrancis.com/chapters/edit/10.4324/9781315676272-23/mount-fuji-history-spiritual-realm-means-preservation-toshihiko-ono-tetsuro-hongo-kiyotatsu-yamamoto-naoya-furuta">symbolic and sacred site of pilgrimage for centuries</a>. Every summer, <a href="https://www.statista.com/statistics/729744/mount-fuji-mountaineer-number-japan/">thousands of people ascend</a> through the clouds to reach the summit. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A group of people gather at a precipice, throwing flower petals and a chicken into the void." src="https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536370/original/file-20230707-15-6jry4i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A worshipper throws a chicken into the crater of Mount Bromo as an offering to the gods during the Yadnya Kasada festival in Probolinggo, East Java, Indonesia.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/IndonesiaHinduFestival/6206d79160dc4253a1829025987fb9b2">AP Photo/Trisnadi</a></span>
</figcaption>
</figure>
<p>For the Tenggerese people on Java, <a href="https://volcano.si.edu/volcano.cfm?vn=263310">Mount Bromo</a> is a deeply sacred site – the abode of gods. Every year they hike up the volcano carrying agricultural products and livestock to be sacrificed during the <a href="https://www.nytimes.com/2021/11/08/travel/yadnya-kasada-volcano-ritual.html">Yadnya Kasada festival</a>. Pilgrims gather at the rim to express gratitude and seek blessings with prayer, chanting and sacred offerings. </p>
<p>In Ecuador, the Quechua people follow a <a href="https://www.encyclopedia.com/literature-and-arts/language-linguistics-and-literary-terms/language-and-linguistics/quechua">religion that combines pre-Columbian and Catholic elements</a>. Local people see the <a href="https://volcano.si.edu/volcano.cfm?vn=352080">Tungurahua volcano</a> as a <a href="https://www.sapiens.org/culture/tungurahua/">familiar but unpredictable matriarch</a> who can offer support and guidance. </p>
<h2>Economic opportunity</h2>
<p>The land surrounding volcanoes often offers significant economic opportunity.</p>
<p>Volcanic soils are <a href="https://doi.org/10.1016/B978-0-12-385938-9.00072-9">among the most fertile in the world</a>. They contain essential minerals and nutrients such as iron, magnesium, calcium, potassium, phosphorus and trace elements that are <a href="https://thedailyfarming.com/farming/what-crops-grow-best-in-volcanic-soil/">essential for plant growth</a>. They also have high organic matter content, good pH balance, high porosity and strong water retention, making them <a href="https://doi.org/10.1016/B978-0-12-385938-9.00072-9">ideal for agriculture</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A mature woman leans against a stone wall with banana trees in the background." src="https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536130/original/file-20230706-22749-l28s65.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The owner of a small banana farm watches as ash comes from the Cumbre Vieja volcano in the Canary island of La Palma, Spain, on Oct. 6, 2021.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/isabel-marãa-who-owns-a-small-piece-of-land-where-she-news-photo/1235764706">Marcos Moreno/Anadolu Agency via Getty Images</a></span>
</figcaption>
</figure>
<p>In addition, volcanic terrains often create unique microclimates that are ideal for growing high-value crops such as <a href="https://www.wineenthusiast.com/basics/advanced-studies/volcanic-soils-wine-science/">grapes</a>, coffee and <a href="https://www.echocommunity.org/en/resources/f3e66825-d4ff-4038-85c1-11cf3b468224">bananas</a>.</p>
<p>Striking landscapes, unique geological features and the thrill of proximity <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-mount-fuji-workshop-focused-how-manage-tourism-active">draw tourists to active volcanoes worldwide</a>. Visitors to sites like the <a href="https://earth.google.com/web/search/Bromo,+Area+Gunung+Bromo,+Podokoyo,+Pasuruan+Regency,+East+Java,+Indonesia/@-7.94249345,112.9530122,2156.2657602a,5671.73576521d,35y,0h,45t,0r/data=CrcBGowBEoUBCiUweDJkZDYzN2FhYWI3OTRhNDE6MHhhZGE0MGQzNmVjZDJhNWRkGdnB0godxR_AIRjs4Sb-PFxAKkpCcm9tbywgQXJlYSBHdW51bmcgQnJvbW8sIFBvZG9rb3lvLCBQYXN1cnVhbiBSZWdlbmN5LCBFYXN0IEphdmEsIEluZG9uZXNpYRgCIAEiJgokCagitvMQb0RAEahkXx0MZURAGUO61niw4SxAISXcEg68uSxAKAI">Bromo Tengger Semeru National Park</a> on Java, <a href="https://www.usgs.gov/volcanoes/kilauea">Mount Kilauea in Hawaii</a> and
<a href="https://whc.unesco.org/en/list/1427/">Mount Etna</a> on the island of Sicily can <a href="https://www.nationalgeographic.com/travel/article/is-volcano-tourism-safe">boost local economies</a> and significantly enhance the livelihoods of residents. </p>
<p>Volcanic landscapes can also offer <a href="https://www.nature.com/articles/s41598-018-33206-3">rich mineral resources</a> such as gold, silver, amethyst and more. For example, the rich volcanic landscape around El Misti in southern Peru is valued for its <a href="https://www.mining-technology.com/projects/cerro-verde-copper-molybdenum-mine/">industrially mined copper and other metals</a>. </p>
<p>On Java, in Indonesia, <a href="https://volcano.si.edu/volcano.cfm?vn=263350">miners still excavate</a> bright yellow <a href="https://www.bbc.com/future/article/20190109-sulphur-mining-at-kawah-ijen-volcano-in-indonesia">sulfur deposits from the active Kawah Ijen</a> volcano crater floor using simple hand tools. They then <a href="https://www.youtube.com/watch?v=E0WT1HtB-Sc">carry the heavy blocks up the volcano’s steep walls to its rim</a>.</p>
<p>Such extraction can stimulate economic growth and create jobs, <a href="https://www.reuters.com/world/americas/peru-declares-state-emergency-restore-copper-production-cuajone-mine-2022-04-20/">but often the wealth is exported</a> and lost to local communities that struggle financially.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photo of an old woman's hand holding a cluster of tomatoes covered in ash." src="https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536118/original/file-20230706-25-rkjej2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A farmer shows her tomatoes after a 2023 Mount Merapi eruption at Tlogolele village, Indonesia.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/farmer-shows-tomatoes-in-her-fields-after-mount-merapi-news-photo/1248214796">Bram Selo/Xinhua via Getty Images</a></span>
</figcaption>
</figure>
<h2>Low-cost land</h2>
<p>Not everyone who lives next to a volcano does so by choice. Poverty can push and trap people there.</p>
<p>At <a href="https://volcano.si.edu/volcano.cfm?vn=263250">Mount Merapi in Indonesia</a> and <a href="https://volcano.si.edu/volcano.cfm?vn=273030">Mount Mayon in the Philippines</a>, two of the world’s most active volcanoes, subsistence farmers live and work on the steep slopes. Because they live closest to the eruption sites, these communities are particularly vulnerable, making rapid evacuation unlikely.</p>
<p>In 2010, <a href="https://web.archive.org/web/20101202120048/http://www.thejakartapost.com/news/2010/11/18/death-toll-fromindonesia039s-volcano-climbs-275.html">250 people were killed by searing gas clouds</a> during an eruption of Mount Merapi. Despite the tragedy, many people who did survive stayed put because leaving their crops behind would mean financial ruin. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scientific mapping of the area around El Misti -- detailing areas most at risk for various types of volcanic destruction." src="https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=793&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=793&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=793&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=997&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=997&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534905/original/file-20230629-27-ra1933.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=997&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A hazard zone map for El Misti in Peru shows probable paths of destruction.</span>
<span class="attribution"><a class="source" href="https://volcano.si.edu/volcano.cfm?vn=354010">Smithsonian Institution Global Volcanism Program, Courtesy of Cobeñasa and others</a></span>
</figcaption>
</figure>
<p>As scientists get better at <a href="https://www.usgs.gov/programs/VHP">predicting eruptions and likely paths of destruction</a>, sometimes the danger of volcanoes can be mitigated with good communication and solid <a href="https://www.cdc.gov/disasters/volcanoes/before.html">evacuation plans</a>. Even so, life beside a volcano is a complex interplay of risk and reward – and one many cannot avoid.</p><img src="https://counter.theconversation.com/content/206977/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Kitchen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>For some people, it’s a choice based on cultural beliefs or economic opportunities provided by the volcano. Other times it’s less a choice than the only option.David Kitchen, Associate Professor of Geology, University of RichmondLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2070312023-07-05T20:05:49Z2023-07-05T20:05:49ZVolcano eruptions are notoriously hard to forecast. A new method using lasers could be the key<figure><img src="https://images.theconversation.com/files/534721/original/file-20230629-28-952crh.jpg?ixlib=rb-1.1.0&rect=105%2C169%2C4298%2C2738&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/etna-eruption-sicily-lava-nature-1560571136">Shutterstock</a></span></figcaption></figure><p>When you hear news reports about volcanoes spewing lava and ash, you may worry about the people nearby. In fact, almost one in ten people around the world <a href="https://www.cambridge.org/core/books/global-volcanic-hazards-and-risk/global-volcanic-hazard-and-risk/E0B20AB275CDB097BF802665DD6DA9A6">live within 100 kilometres of an active volcano</a>. For those living close to volcanoes, farming on their fertile soils, or visiting their spectacular landscapes, it is crucial to understand the drivers of eruption. </p>
<p>Why is the volcano erupting? How will the eruption evolve? When will it finish?</p>
<p>Our <a href="http://www.science.org/doi/10.1126/sciadv.adg4813">new research</a> published today in Science Advances applies laser technology to read into the chemical composition of erupted magma over time. </p>
<p>Because the chemistry of magmas affects their fluidity, explosivity and hazard potential, our work could help future monitoring and forecasting of the evolution of volcanic eruptions. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-cant-we-predict-when-a-volcano-will-erupt-53898">Why can't we predict when a volcano will erupt?</a>
</strong>
</em>
</p>
<hr>
<h2>Untangling the chemistry of erupted melt</h2>
<p>Magma – molten rock – is composed of liquid (known as “melt”), gas and crystals that grow as the temperature of the magma drops during its journey up to Earth’s surface.</p>
<p>When the magma erupts to become a lava flow, it will release the gas (which contains water vapour, carbon dioxide, sulphur dioxide and other compounds) and cool down into a volcanic rock. This rock contains crystals cooled slowly inside the volcano, embedded in a finer rock matrix cooled rapidly at the surface.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A black background with colourful crystals in it" src="https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=962&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=962&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=962&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1209&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1209&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534728/original/file-20230629-27-cuhqv4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1209&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Microscope view of lava erupted on October 24 2021 at La Palma, with large colourful crystals in a fine-grained black rock matrix which we analyse via laser. The image is in cross-polarised transmitted light (5mm scale bar).</span>
<span class="attribution"><span class="source">A. MacDonald</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>As a result, volcanic rocks can <a href="https://theconversation.com/there-she-blows-the-internal-magma-filter-that-prompts-ocean-island-volcanoes-to-erupt-167358">look a bit like “rocky road” chocolate</a>. The <a href="https://theconversation.com/volcano-crystals-could-make-it-easier-to-predict-eruptions-90558">crystals</a> formed in the guts of the volcano are excellent archives of the run-up to eruption. However, the crystals can get in the way when we want to focus on the melt that carries them to the surface, and how the melt properties vary throughout the eruption. </p>
<p>To isolate the melt signal, we used an ultraviolet laser, similar to the ones used for eye surgery, to blast the rock matrix between larger crystals.</p>
<p>We then analysed the laser-generated particles by <a href="https://www.britannica.com/science/mass-spectrometry">mass spectrometry</a> to determine the chemical composition of the volcanic matrix. The method allows for a rapid chemical analysis.</p>
<p>This provides a faster and more detailed measure of melt chemistry and its evolution over time, compared to traditional analysis of the entire rock, or to painstaking separation of matrix and crystal fragments from crushed rock samples. Even if we call the crystals “large”, they are often as small as a grain of salt (or up to a chickpea in size if you are lucky!) and difficult to remove. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-pulse-of-a-volcano-can-be-used-to-help-predict-its-next-eruption-117005">The 'pulse' of a volcano can be used to help predict its next eruption</a>
</strong>
</em>
</p>
<hr>
<h2>A destructive disaster in the Canary Islands</h2>
<p>Our study focused on the <a href="https://en.wikipedia.org/wiki/2021_Cumbre_Vieja_volcanic_eruption">2021 eruption at La Palma</a>, the most destructive volcanic eruption on historical record in the Canary Islands.</p>
<p>From September to December 2021, a total of 160 million cubic metres of lava covered more than 12 square kilometres of land. It destroyed more than 1,600 homes, forced the evacuation of more than 7,000 people and generated losses of more than <a href="https://ec.europa.eu/regional_policy/en/newsroom/news/2022/03/22-03-2022-eu-solidarity-eur5-4-million-of-advance-payments-to-spain-following-the-volcanic-eruption-in-la-palma">€860 million</a> (AU$1.4 billion). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Aerial photo of houses with a river of lava flowing in between" src="https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534724/original/file-20230629-21-uph29m.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Drone image of a lava flow from the 2021 La Palma eruption (December 4 2021, houses for scale).</span>
<span class="attribution"><span class="source">Instituto Geologico y Minero de Espana</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We analysed lava samples collected systematically by our collaborators in Spain throughout the three months of eruption. These are precious samples as we know their exact eruption day, and many of the sampling sites are now covered by later lavas from the eruption. </p>
<p>Using the laser-powered method, we could see variations in lava chemistry linked to changes in earthquakes and sulphur dioxide emissions, as well as eruption style and the resulting hazards. This included a change from thick lavas that acted as a bulldozer at the start of the eruption, to runny lavas that created rapid <a href="https://twitter.com/i_ameztoy/status/1665062180713103362?s=20">lava rivers</a> and lava tunnels later in the eruption.</p>
<p>We also found a key change in lava chemistry about two weeks before the eruption ended, which suggests cooling of the magma due to a dropping magma supply.</p>
<p>Similar changes could be monitored as a signal of eruption wind-down in future eruptions around the world. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534729/original/file-20230629-23-v10rmi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Early lavas from the 2021 La Palma eruption were voluminous and blocky, acting as a hot ‘bulldozer’ (September 22 2021, traffic sign for scale).</span>
<span class="attribution"><span class="source">JJ Coello Bravo</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Forecasting volcanic activity</h2>
<p>We cannot prevent volcanoes from erupting, and we cannot yet travel inside them <a href="https://en.wikipedia.org/wiki/Journey_to_the_Center_of_the_Earth">like French sci-fi author Jules Verne once envisioned</a>. But <a href="https://www.usgs.gov/programs/VHP/comprehensive-monitoring-provides-timely-warnings-volcano-reawakening">volcano monitoring</a> has improved enormously in the last few decades to allow us to indirectly ‘peek into’ volcanoes and better forecast their activity.</p>
<p>Our work aims to provide a laboratory tool for testing volcanic samples collected during future eruptions. The goal is to read into the evolution of eruptions, to understand why they start and when they will end. </p>
<p>With <a href="https://volcano.si.edu/">about 50 volcanoes erupting</a> at any given time around the world, you will soon see another volcano erupting in the news. This time, you can consider the importance of volcano science to improve our understanding of how volcanoes work and what drives them to erupt, to protect the people around them. </p>
<hr>
<p><em>Correction: an earlier version of this article stated the 2021 La Palma eruption released 160 cubic metres of lava. The correct figure is 160 million cubic metres.</em></p><img src="https://counter.theconversation.com/content/207031/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Teresa Ubide works for The University of Queensland. She receives funding from the Australian Research Council, AuScope-NCRIS, and The University of Queensland. </span></em></p><p class="fine-print"><em><span>Alice MacDonald is a PhD Student at The University of Queensland and receives a RTP PhD Stipend from UQ. </span></em></p><p class="fine-print"><em><span><a href="mailto:jack.mulder@adelaide.edu.au">jack.mulder@adelaide.edu.au</a> receives funding from the Australian Research Council, AuScope-NCRIS, The University of Adelaide. </span></em></p>One in ten people around the world live near an active volcano. Understanding the drivers of eruptions is crucial.Teresa Ubide, Associate Professor - Igneous Petrology/Volcanology, The University of QueenslandAlice MacDonald, PhD Student, The University of QueenslandJack Mulder, Lecturer, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1957042023-05-01T12:10:20Z2023-05-01T12:10:20ZWhat causes volcanoes to erupt?<figure><img src="https://images.theconversation.com/files/501671/original/file-20221218-11129-2abr3x.jpg?ixlib=rb-1.1.0&rect=7%2C0%2C4985%2C3323&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An aerial view of the Mauna Loa volcano, which erupted on the island of Hawaii in December 2022.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-an-aerial-view-lava-erupts-from-the-mauna-loa-volcano-on-news-photo/1245459430?phrase=Mauna%20Loa%20volcano%202022&adppopup=true">Andrew Richard Hara/Getty Images News</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>What causes volcanoes to erupt? – Avery, age 8, Los Angeles</strong></p>
</blockquote>
<hr>
<p>On Nov. 27, 2022, Mauna Loa – the world’s largest active volcano – <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-mauna-loa-reawakens-0">erupted on the island of Hawaii</a>. For days, fountains of lava, boiling at more than 2,000 degrees Fahrenheit (1,100 degrees Celsius), spewed upward and flowed down the mountain’s sides. </p>
<p>For tens of millions of people around the world, the videos were a mesmerizing sight. Then, a few weeks later, the eruption ended. Fortunately, there were no known deaths, and no major property damage. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/F0tmu-zaXig?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Mauna Loa is the world’s largest active volcano.</span></figcaption>
</figure>
<p>About a week later, Mount Semeru in East Java, Indonesia, <a href="https://volcano.si.edu/volcano.cfm?vn=263300">erupted a mix of ash, gas and hot rocks</a>. The plumes rose a mile above the mountain’s summit. Thousands <a href="https://www.pbs.org/newshour/world/new-eruption-of-indonesias-mt-semeru-unleashes-lava-river-volcanic-ash">living in the vicinity were evacuated</a>; many wore masks to protect themselves from the ash-filled air. Mount Semeru has continued to erupt for months.</p>
<p>I am a geologist who <a href="https://scholar.google.com/citations?user=4Q8uMqUAAAAJ&hl=en&oi=ao">studies minerals in volcanic rocks</a>. I want to learn more about what causes volcanoes to erupt. Millions of people <a href="https://www.discovery.com/exploration/People-Live-Near-Active-Volcanoes">live near an active volcano</a> – that is, one of the 1,328 volcanoes worldwide that have <a href="https://volcano.si.edu/faq/index.cfm?question=activevolcanoes">erupted over the past 12,000 years</a>. </p>
<p>At any given time, 20 to 50 of these <a href="https://volcano.si.edu/gvp_currenteruptions.cfm">active volcanoes are erupting</a>. The proximity of people and buildings makes it important to study volcanoes and understand the hazards. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photograph of the city of Naples, Italy, with Mount Vesuvius in the background." src="https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=370&fit=crop&dpr=1 600w, https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=370&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=370&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=465&fit=crop&dpr=1 754w, https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=465&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/502804/original/file-20230102-22-tpygfq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=465&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mount Vesuvius, about 6 miles east of Naples, Italy, is still an active volcano. In A.D. 79, Vesuvius erupted and destroyed the city of Pompeii.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/travelling-in-italy-royalty-free-image/906204248?phrase=volcanoes%20mount%20vesuvius&adppopup=true">Antonio Busiello/Moment via Getty Images</a></span>
</figcaption>
</figure>
<h2>How volcanoes blow their stacks</h2>
<p>The center of the Earth is <a href="https://earthhow.com/inside-earth-crust-core-mantle/">called the core</a>; the next layer up is the mantle; the outermost layer is the crust. </p>
<p>Over time, <a href="https://kids.kiddle.co/Magma">magma</a> – which is melted rock mixed with gas and mineral crystals – accumulates in an underground chamber beneath the volcano. The magma at Mauna Loa forms when a <a href="https://www.cbsnews.com/news/where-does-mauna-loa-lava-come-from/">hot mantle plume</a> – think of a conveyor of heat – partly melts rock in the mantle. </p>
<p>The volcano is essentially an <a href="https://www.natgeokids.com/uk/discover/geography/physical-geography/volcano-facts/">opening that lets magma out</a> onto the surface of the Earth. Once released from the volcano, the magma is called lava. </p>
<p>In the months leading to its eruption, scientists noted <a href="https://www.usgs.gov/observatories/hvo">increased earthquakes and a bulging of Mauna Loa</a>, like a balloon being inflated. These signs suggested that more magma was making its way upward, because pressure from rising magma can expand the sides of a volcano and cause rocks to shift and break, which leads to earthquakes.</p>
<p>Typically, for an eruption to occur, enough magma must <a href="https://www.usgs.gov/programs/VHP/about-volcanoes">accumulate in the chamber under the volcano</a>. Then something needs to trigger the eruption. That could be an injection of new magma into the chamber, a buildup of gases within the volcano, or a landslide that removes material from the top of a volcano.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/XLF_lMY2gu8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The eruption on Mount Semeru forced an evacuation of nearly 2,000 nearby residents.</span></figcaption>
</figure>
<h2>Types of volcanoes</h2>
<p>Mauna Loa is a <a href="https://study.com/academy/lesson/shield-volcano-facts-lesson-for-kids.html#:%7E">shield volcano</a>, built up over thousands of years through lava eruptions. Its sides slope gently downward in all directions. </p>
<p>But Mount Semeru is different – it’s a <a href="https://study.com/academy/lesson/composite-volcano-facts-lesson-for-kids.html#:%7E">composite volcano</a>, also known as a stratovolcano, with steep sides that come to a point at the top, like an upside-down sugar cone. </p>
<p>Semeru’s most recent eruption started when heavy rains <a href="https://www.cnn.com/2021/12/08/asia/indonesia-mount-semeru-volcano-eruption-cimate-intl/index.html">washed away rocks near the top of the volcano</a>. That allowed gas to escape – and ash to start erupting. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A motorbike, and the ground around it, covered in ash." src="https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517451/original/file-20230324-24-crlmkn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">After the eruption at Mount Semeru, nearby villages were covered in volcanic ash.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/motorbike-is-covered-with-volcanic-ashes-after-mount-semeru-news-photo/1237024024?adppopup=true">Bayu Novanta/Xinhua News Agency via Getty Images</a></span>
</figcaption>
</figure>
<h2>The dangers</h2>
<p>Many hazards are associated with erupting volcanoes: lava flows, acidic gases, ash and <a href="https://www.usgs.gov/observatories/cascades-volcano-observatory/lahars-most-threatening-volcanic-hazard-cascades#:%7E">lahars</a>, which are dangerous flows of water, ash and rock that <a href="https://www.usgs.gov/programs/VHP/lahars-move-rapidly-down-valleys-rivers-concrete">run miles down the steep slopes of volcanoes</a>, sometimes <a href="https://www.usgs.gov/programs/VHP/lahars-move-rapidly-down-valleys-rivers-concrete#:%7E">at over 100 miles per hour</a>. The force of lahars can move huge boulders and destroy bridges and buildings. </p>
<p>Mount Semeru’s recent eruption <a href="https://www.usgs.gov/programs/VHP/ashfall-most-widespread-and-frequent-volcanic-hazard">covered nearby villages with ash</a> – tiny particles of rock that can go deep into lungs, causing irritation and making it hard to breathe. </p>
<p>As falling ash accumulates, it can smother crops, contaminate water supplies and trigger the collapse of buildings. Newly fallen dry ash weighs <a href="https://mil.wa.gov/asset/5ba4200a0b533#:%7E:text=Ash%20accumulates%20like%20heavy%20snowfall,Wet%20ash%20is%20slippery.">10 to 20 times more than snow</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/3Jxeh-yAXek?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Below the surface, Earth is always moving and changing.</span></figcaption>
</figure>
<p>Generally, scientists don’t try to stop volcanoes from erupting. They are a natural part of the Earth. But monitoring volcanoes is critical. People need an early warning of an eruption <a href="https://www.usgs.gov/programs/VHP/understanding-volcanic-hazards-can-save-lives">so they can move out of harm’s way</a>. </p>
<p>While we cannot predict the exact time of an eruption, scientists are learning more about what causes them, and how to protect people who live near them. </p>
<p>What’s critical: warning systems for lahars, planned evacuation routes in areas threatened by volcanoes, and excellent communication between the scientists at volcanic monitoring stations and government agencies who can let people know when a volcano is about to go. </p>
<hr>
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<p class="fine-print"><em><span>Rachel Beane receives funding from Bowdoin College and the National Science Foundation. She is affiliated with the Harpswell Heritage Land Trust. </span></em></p>As they shape the Earth, volcanoes inspire and terrify humans.Rachel Beane, Professor of Natural Sciences, Bowdoin CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1957032022-12-06T13:34:43Z2022-12-06T13:34:43ZNative Hawaiians believe volcanoes are alive and should be treated like people, with distinct rights and responsibilities<figure><img src="https://images.theconversation.com/files/499069/original/file-20221205-22-ww08xg.jpg?ixlib=rb-1.1.0&rect=57%2C8%2C5398%2C3612&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hawaii's Mauna Loa's volcano is erupting for the first time in nearly 40 years.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-gather-on-top-of-a-hill-to-watch-mauna-loa-erupts-news-photo/1245294420?phrase=mauna%20loa&adppopup=true">Tayfun Coskun/Anadolu Agency via Getty Images</a></span></figcaption></figure><p>Hawaii’s largest and oldest volcano, <a href="https://www.usgs.gov/news/featured-story/mauna-loa-has-begun-erupting">Mauna Loa, began erupting</a> on Nov. 27, 2022, with lava flowing miles away downhill. The last eruption, which lasted three weeks, <a href="https://www.khon2.com/local-news/mauna-loa-eruption/last-mauna-loa-eruption-was-nearly-40-years-ago/">was nearly 40 years ago</a>. </p>
<p>It is not clear how long this eruption will last, but for many Native Hawaiians, <a href="https://www.cnn.com/videos/us/2022/12/04/hawaii-mauna-loa-volcano-eruption-culture-pele-ilihia-gionson-intv-whitfield-nrtf.cnn">it is a profound spiritual experience</a>. </p>
<p>As an <a href="https://ais.arizona.edu/users/richard-stoffle">anthropologist</a>, I have conducted <a href="https://doi.org/10.3390/land11020196">nine studies</a> on traditional Native American cultural relationships with volcanic lava flows. As in most Native American cultures, <a href="https://www.researchgate.net/profile/Alex-Ruuska/publication/289537668_Ethnology_of_Volcanoes_Quali-Signs_and_the_Cultural_Centrality_of_Self-Voiced_Places/links/568fd8f608aecd716aedc011/Ethnology-of-Volcanoes-Quali-Signs-and-the-Cultural-Centrality-of-Self-Voiced-Places.pdf">Native Hawaiians’ beliefs hold</a> that Mauna Loa and other volcanoes are alive, and their eruptions are how the Earth is reborn. The volcano is like the Earth’s mother.</p>
<p>Since the volcano is alive, <a href="https://www.researchgate.net/publication/313558717_Talking_With_Nature_Southern_Paiute_Epistemology_and_The_Double_Hermeneutic_with_a_Living_Planet">it must be treated like a person</a> with rights and responsibilities and differently than if it were just flowing hot magma.
Not just the volcano – all elements of the Earth <a href="https://experts.arizona.edu/en/publications/living-universe-or-geofacts-stone-arches-in-utah-national-parks-e">are perceived as being alive</a>, with feelings, the ability to speak and the power to do things they wish.</p>
<p>This view of the living Earth defines as alive the plants that grow on the volcano, the wind that passes over it, the birds that nest near it, the water that flows from it after rains and the oceans it touches. </p>
<h2>The power of volcanoes</h2>
<p>Native Hawaiians maintain that since the Earth’s creation, volcanoes’ elements – earth, wind and fire – <a href="https://experts.arizona.edu/en/publications/living-universe-or-geofacts-stone-arches-in-utah-national-parks-e">have talked</a>. They believe that these elements have humanlike rights, such as to be heard and to have goals. Crystals, obsidian, basalt boulders and other products of volcanic activity each are alive, and all have roles in the lives of humans.</p>
<p>Interactions between the earth elements, the volcano and humans are perceived as continuous because living natural elements change and <a href="https://doi.org/10.3390/land11020196">thus need to adapt</a> to new conditions together with each other and people.</p>
<p>Native American scholar and spokesperson <a href="https://blogs.loc.gov/law/2016/11/remembering-vine-deloria-jr/">Vine Deloria Jr.</a> convened a Native Science of Volcanoes meeting in Albuquerque, New Mexico, in 2005. Among those who attended the meeting were this author and Native people from Washington state, Oregon, California, Arizona, Utah, Nevada and Hawaii, including elders from the Shoshone Bannock, Yakama, Owens Valley Paiute, Southern Paiute, Hopi, Nisqually, Winnemen-Wintu, Navajo and Klamath tribes.</p>
<p>These speakers said they regarded the volcanoes as living beings who, under certain circumstances, would share power and knowledge with humans. According to these elders, the volcano is a place where ceremonies are performed. The ceremonies are both an act of respect and a request for guidance. </p>
<p>Indigenous people believe their welfare and the Earth’s ecological balance are dependent on their continued and appropriate interactions with this living being.</p>
<h2>Pilgrimage and rituals</h2>
<p>Over tens of thousands of years, Native people have traveled to communicate with the same volcanoes during ceremonies. People traveled known physical and spiritual trails during these journeys. </p>
<p>Evidence shows that when pilgrims arrived at a destination volcano, they embedded the landscape with rock peckings, paintings, stone cairns, shrines, incised stones and many offerings. They sang and <a href="https://www.semanticscholar.org/paper/Puha-Po-to-Kavaicuwac%3A-a-Southern-Paiute-Pilgrimage-Vlack/fdd762ac2eb461a5c8e6d143df37e3197608d6c0">documented their relationship</a> with the volcano. </p>
<p>During the mid-11th century lava flows at Sunset Crater, Arizona, and Little Spring, Arizona, people <a href="https://doi.org/10.1007/978-3-030-78040-1_2">placed corn and painted pots</a> on the edge of hornitos – conical structures produced by bubbling lava. When new lava splashes occurred, the resulting stones were embedded with corn imprints and pot shards. These were knocked off the edge before they could cool. The rocks were then taken to a nearby location and became a part of the walls of a ceremonial structure. </p>
<h2>Management policies</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of Hawaii showing the location of Mauna Loa." src="https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499070/original/file-20221205-20-sjtgq6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The eruptions of Mauna Loa raise the question of whether the volcano is a living being or inert.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/hawaii-royalty-free-image/121043074?phrase=mauna%20loa&adppopup=true">KeithBinns/Collections E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>Studies involving Native tribes and U.S. federal agencies have documented that the living Earth belief is <a href="https://fulcrum.bookstore.ipgbook.com/red-earth--white-lies-products-9781555913885.php">broadly shared in North America and Hawaii</a>. But Native peoples and their beliefs have not often been involved in land management policies and interpretations. </p>
<p>This, as I understand, is because of three main reasons: First, over the centuries, many Western scientists have believed that only they possess accurate knowledge about natural processes. Second, federal and state land managers have been given the legal responsibility to properly manage their parks and are reluctant to share power. And lastly, land managers don’t have the cultural knowledge to understand Native American beliefs or how to communicate with volcanoes. </p>
<p>Native people believe their ceremonial interactions with volcanoes result in the shared knowledge, which <a href="https://www.doi.org/10.1007/978-3-030-78040-1">some call Native Science</a>. They believe that volcanoes express ideas during ceremonies about how to keep themselves, the people and the world in balance. People can take this communication and act on it. But when Native beliefs are not perceived as science and thus not seen to be true or useful for management or interpretations, it creates what is known as an “<a href="https://www.doi.org/10.1007/978-3-030-78040-1">epistemological divide</a>. This hampers cross-cultural communication. </p>
<p>The eruptions of Mauna Loa are once again raising important questions about whether the volcano is a living being or inert. They also prompt questions about whether the eruption is for the benefit of humans or simply a threatening geological event that has no purpose. </p>
<p>The answer to these questions will influence how the volcano will be interpreted in the future for visitors and managed by geologists and environments.</p><img src="https://counter.theconversation.com/content/195703/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard W Stoffle receives funding from various federal organizations. </span></em></p>The eruption of Mauna Loa is a profound spiritual experience for many Native Hawaiians. An anthropologist explains Native American beliefs on the living Earth and volcanic lava.Richard W Stoffle, Professor of Anthropology, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1956332022-11-30T13:44:16Z2022-11-30T13:44:16ZWhere Mauna Loa’s lava is coming from – and why Hawaii’s volcanoes are different from most<figure><img src="https://images.theconversation.com/files/498437/original/file-20221201-6346-syova6.jpeg?ixlib=rb-1.1.0&rect=2568%2C1769%2C2083%2C1338&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Magma fountains through a fissure on Mauna Loa, becoming lava, on Nov. 30, 2022.
</span> <span class="attribution"><a class="source" href="https://www.usgs.gov/media/images/november-30-2022-mauna-loa-fissure-3"> K. Mulliken/USGS</a></span></figcaption></figure><p><em>Hawaii’s Mauna Loa, the world’s largest active volcano, began sending up <a href="https://www.usgs.gov/volcanoes/mauna-loa/mauna-loa-eruption-webpage">fountains of glowing rock</a> and spilling lava from fissures as its first eruption in <a href="https://www.usgs.gov/volcanoes/mauna-loa">nearly four decades</a> began on Nov. 27, 2022.</em> </p>
<p><em>Where does that molten rock come from?</em></p>
<p><em>We asked <a href="https://scholar.google.com/citations?user=a7D-WawAAAAJ&hl=en">Gabi Laske</a>, a geophysicist at the University of California-San Diego who led one of the first projects to map the deep plumbing that feeds the Hawaiian Islands’ volcanoes, to explain.</em> </p>
<h2>Where is the magma surfacing at Mauna Loa coming from?</h2>
<p>The magma that comes out of Mauna Loa comes from a series of magma chambers found between about 1 and 25 miles (2 and 40 km) below the surface. These magma chambers are only temporary storage places with magma and gases, and are not where the magma originally came from.</p>
<p>The origin is much deeper in <a href="https://pubs.usgs.gov/gip/dynamic/inside.html">Earth’s mantle</a>, perhaps more than 620 miles (1,000 km) deep. Some scientists even postulate that the magma comes from a <a href="https://www.usgs.gov/observatories/hvo/news/volcano-watch-exploring-deep-source-hawaiian-volcanoes">depth of 1,800 miles (2,900 km)</a>, where the mantle meets Earth’s core.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498078/original/file-20221129-14-85b5yv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An illustration suggests what Hawaii’s mantle plume might look like.</span>
<span class="attribution"><span class="source">Joel E Robinson/USGS</span></span>
</figcaption>
</figure>
<p>Earth’s crust is made up of tectonic plates that are slowly moving, at about the same speed as a fingernail grows. Volcanoes typically occur where these plates either move away from each other or where one pushes beneath another. But volcanoes can also be in the middle of plates, as Hawaii’s volcanoes are <a href="https://www.usgs.gov/media/images/pacific-plate-boundaries-and-relative-motion">in the Pacific Plate</a>.</p>
<p>The crust and mantle that comprise the Pacific Plate cracks at different places as it moves northwestward. Beneath Hawaii, magma can move upward through the cracks to feed different volcanoes on the surface. The same thing happens at Maui’s Haleakala, <a href="https://www.usgs.gov/volcanoes/haleakal%C4%81">which last erupted</a> about 250 years ago.</p>
<h2>How does molten rock travel from deep in Earth’s mantle, and what exactly is a mantle plume?</h2>
<p>Scientists hypothesize that the mantle is not made of uniform rock. Instead, <a href="https://doi.org/10.1038/s41561-019-0368-9">differences in the type</a> of mantle rock make it melt at <a href="https://openoregon.pressbooks.pub/earthscience/chapter/4-1-magma-and-how-it-forms/">different temperatures</a>. Mantle rock is solid at some places, while it starts to melt at other places.</p>
<p>The partially molten rock becomes buoyant and ascends toward the surface. The ascending mantle rock is what makes a mantle plume. Because the overlying pressure lessens as the rock ascends, it melts more and more, and eventually collects in the magma chamber. If a large enough opening exists at the surface, and enough volcanic gases have collected in the magma chamber, the magma is forced to the surface in a volcanic eruption.</p>
<figure class="align-center ">
<img alt="A cross section of the earth shows two potentially sources for the mantle plume, one starting much deeper and flowing a squiggly route as seismic imaging suggests." src="https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498109/original/file-20221129-20-2d4cyv.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The origin of the magma may be more than 620 miles deep, and some scientists have suggested it could come from a depth of 1,800 miles, where the mantle meets Earth’s core.</span>
<span class="attribution"><span class="source">Gabi Laske</span></span>
</figcaption>
</figure>
<p>Seismic imaging by research teams I’m involved with has shown that Hawaii’s mantle plume <a href="https://doi.org/10.1126/science.1180165">comes from deep inside the mantle</a>.</p>
<p>But the plume is not a straight pipe as some concept figures suggest. Instead, it has <a href="https://doi.org/10.1038/ngeo1878">twists and turns</a>, originally coming from the southeast, but then turning toward the west of Hawaii as the plume reaches into the shallower mantle. Cracks in the Pacific Plate then channel the magma upward toward the magma chamber beneath the island of Hawaii.</p>
<h2>Why does Hawaii typically see less dramatic eruptions than other locations?</h2>
<p>Hawaii is in the middle of an oceanic plate. In fact, it is the most isolated volcanic hot spot on Earth, far away from any plate boundary.</p>
<p>Oceanic magma is very different from continental magma. It has a different chemical composition and flows much more easily. So, the magma is <a href="https://geowiki.ucsd.edu/sio15/topics/topic09.html">less prone to clog volcanic vents</a> on its ascent, which would ultimately lead to more explosive volcanism.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/9DUexRQfNBA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Thermal imaging shows the Mauna Loa eruption, which began around 11:30 p.m. local time on Nov. 27, 2022. Temperatures are in Celsius. USGS.</span></figcaption>
</figure>
<h2>How do scientists know what is happening under the surface?</h2>
<p>Volcanic activity is monitored with many different instruments.</p>
<p>The perhaps simplest to understand is GPS. The way scientists use GPS is different from that of everyday life. It can detect minuscule movements of a few centimeters. On volcanoes, any upward movement on the surface detected by GPS indicates that something is pushing from underneath.</p>
<p>Even more sensitive are <a href="https://www.usgs.gov/programs/VHP/tiltmeters-and-strainmeters-measure-subtle-changes-ground-slope-and-shape-volcanoes">tiltmeters</a>, which are in essence the same as bubble levels that people use to hang pictures on a wall. Any change in the tilt on a volcano slope indicates that the volcano is “breathing,” again because of magma moving below.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of the island of Hawaii, showing Mauna Loa and the lava flow paths since the late 1800s. There have been several eruptions and they tend to follow two routes." src="https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=776&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=776&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=776&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=976&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=976&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498080/original/file-20221129-14-pr28xg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=976&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mauna Loa has a history of eruptions. Here’s where the lava tends to go.</span>
<span class="attribution"><a class="source" href="https://www.usgs.gov/volcanoes/mauna-loa/geology-and-history">USGS</a></span>
</figcaption>
</figure>
<p>A very important tool is watching for seismic activity.</p>
<p>Volcanoes like Hawaii’s are monitored with a large network of seismographs. Any movement of magma below will cause tremors that are picked up by the <a href="https://www.usgs.gov/programs/VHP/networks-multiple-seismometers-are-necessary-adequately-monitor-volcanoes">seismometers</a>. A few weeks before the eruption of Mauna Loa, scientists noticed that the tremors came from ever shallower depths, indicating that magma was rising and an eruption might be imminent. This <a href="https://apnews.com/article/science-hawaii-kilauea-mauna-loa-14f7596e22b08a44600caa5f185b5b18">allowed scientists to warn the public</a>.</p>
<p>Other ways that volcanic activity is monitored includes chemical analysis of gases coming out <a href="https://www.usgs.gov/news/earthword-fumarole">through fumaroles</a> – holes or cracks through which volcanic gases escape. If the composition changes or activity increases, that’s a pretty clear indication that the volcano is changing.</p><img src="https://counter.theconversation.com/content/195633/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gabi Laske receives funding from the National Science Foundation. </span></em></p>A scientist who led one of the first projects to map the Hawaiian Islands’ deep volcanic plumbing explains what’s going on under the surface as Mauna Loa erupts.Gabi Laske, Professor of Geophysics, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1904312022-09-22T20:15:45Z2022-09-22T20:15:45ZCurious Kids: how is lava made?<figure><img src="https://images.theconversation.com/files/484971/original/file-20220915-40845-spyrev.jpg?ixlib=rb-1.1.0&rect=15%2C57%2C3469%2C2450&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">ImageBank4u/Shutterstock</span></span></figcaption></figure><blockquote>
<p>How is lava made? – Leon, age 7, Sydney, Australia </p>
</blockquote>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
<p>Thank you for a great question Leon! </p>
<p>Have you ever seen lava? What does it look like to you? Lava can be red, fiery and liquid or cool, dark and solid, like in the picture above. </p>
<p>In the picture you can see red hot lava, flowing over black solid rock where the lava has cooled. Lava is molten rock, melted because of very high temperatures, much, much hotter than you would see on the surface of the earth.</p>
<p>Can you imagine how hot it must be to melt rock? This gives a clue about how lava is made, somewhere with very high temperatures below Earth’s surface. </p>
<p>While underground, the liquid rock is called magma; it becomes lava when it flows onto the planet’s surface, usually through a volcano. When the lava cools – that’s the dark solid ground you see in the image – it is called “igneous” rock. This means “fire” in Latin (scientists use a lot of Latin words), so it is fire rock.</p>
<p>To understand how lava is made and where it comes from, we need to journey below Earth’s surface – which we can’t do, because it would be too dangerous. Imagine trying to travel somewhere hot enough to melt rock, what would that do to you?</p>
<p>Instead, we can look at the structure of Earth in the image below and imagine the journey.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chart showing Earth's crust, upper mantle, lower mantle, inner core like a dissected gumball" src="https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484976/original/file-20220915-46145-spyrev.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earth has several layers in its structure, from surface all the way to the solid core.</span>
<span class="attribution"><span class="source">Naeblys/Shutterstock</span></span>
</figcaption>
</figure>
<p>We would travel down through Earth’s crust, into the mantle and then into the core. Once there, we would discover that the crust and mantle are mostly solid rock. After the mantle we would notice the liquid outer core and then the solid metal inner core. </p>
<p>In Earth’s core the temperatures are very hot, <a href="https://www.nationalgeographic.com/science/article/earths-interior">usually between 5,000 and 7,000 degrees Celsius</a>. Think about this to compare: chocolate starts melting at around 80°C and tap water boils at 100°C. This very hot core acts like an oven for Earth, heating it from within.</p>
<p>Along the way we might find some magma in the mantle where it is made, in a space between the outer mantle and Earth’s crust. Magma is formed through heat and pressure – imagine squeezing a ball of plasticine as hard as you can: that is you putting pressure on the ball. While the mantle is not as hot as the liquid core, there is a lot more pressure. The pressure is caused by movement in the rocky mantle, pressing against the crust.</p>
<p>This pressure, and the temperatures from Earth’s “oven” at the core, cause rock to melt and magma is formed. The magma moves to Earth’s surface through openings – sometimes these openings are volcanoes – and forms new crust. </p>
<p>Often the new crust forms into islands, like many of the Pacific islands. This happens because liquid comes out through openings on the sea floor and cools, forming land.</p>
<p>You can watch this video for the story from Mother Earth herself. But be warned: never put rocks in a fire to try and melt them, some might explode! I’ll let you ask about that another time.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/SoJ8cRnbbps?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure><img src="https://counter.theconversation.com/content/190431/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janice Crerar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Earth has liquid rock inside. Here’s what happens to that rock to make lava happen.Janice Crerar, Lecturer in Education, Charles Darwin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1709192022-01-03T13:42:00Z2022-01-03T13:42:00ZWhy can’t we throw all our trash into a volcano and burn it up?<figure><img src="https://images.theconversation.com/files/435952/original/file-20211206-141213-f6fuq.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lava flows from a fissure in the aftermath of eruptions from the Kilauea volcano on Hawaii's Big Island, May 22, 2018. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/lava-flows-from-a-fissure-in-the-aftermath-of-eruptions-news-photo/962057980">Andrew Richard Hara/Ena Media Hawaii via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>Why can’t we throw all our trash into a volcano and burn it up? – Georgine T.</strong></p>
</blockquote>
<hr>
<p>It’s true that lava is hot enough to burn up some of our trash. When Kilauea erupted on the Big island of Hawaii in 2018, the lava flows were <a href="https://www.usgs.gov/media/images/lava-temperatures-were-about-2000-degrees-fahrenheit">hotter than 2,000 degrees Fahrenheit (1,100 Celsius)</a>. That’s hotter than <a href="https://solarsystem.nasa.gov/planets/venus/overview/">the surface of the planet Venus</a>, and hot enough to melt many rocks. It’s also as hot as waste incinerators, which usually burn garbage at <a href="https://www3.epa.gov/ttnchie1/mkb/documents/fthermal.pdf">1,800 to 2,200 F</a> (1,000-1,200 C). </p>
<p>[<em>Over 140,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140ksignup">Sign up today</a>.]</p>
<p>But not all lavas are the same temperature. The eruptions in Hawaii produce a type of lava called <a href="https://volcanoes.usgs.gov/vsc/glossary/basalt.html">basalt</a>. Basalt is much hotter and more fluid than the lavas that erupt at other volcanoes, like the thicker <a href="https://volcanoes.usgs.gov/vsc/glossary/dacite.html">dacite lava</a> that erupts at Mount St. Helens in Washington state. For example, the 2004-2008 eruption at Mount St. Helens produced a lava dome with surface temperatures less than about 1,300 F (704 C). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic on number and location of U.S. volcanoes" src="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There are 161 volcanoes in 14 U.S. states and territories. Scientists monitor them and warn nearby communities if they see signs that a volcano may erupt.</span>
<span class="attribution"><a class="source" href="https://www.usgs.gov/media/images/us-one-earths-most-volcanically-active-countries">USGS</a></span>
</figcaption>
</figure>
<p>Beyond temperature, there are other good reasons not to burn our trash in volcanoes. First, although lava at 2,000 degrees F can melt many materials in our trash – including food scraps, paper, plastics, glass and some metals – it’s not hot enough to melt many other common materials, including <a href="https://www.americanelements.com/meltingpoint.html">steel, nickel and iron</a>. </p>
<p>Second, there aren’t many volcanoes on Earth that have lava lakes, or bowl-like craters full of lava, that we could dump trash into. Of all of the thousands of volcanoes on Earth, scientists know of only <a href="https://www.bbc.co.uk/newsround/48856373">eight with active lava lakes</a>. They include <a href="https://www.usgs.gov/media/images/new-usgs-video-about-k-laueas-summit-eruption-now-online">Kilauea</a>, <a href="https://volcano.si.edu/volcano.cfm?vn=390020">Mount Erebus in Antarctica</a> and <a href="https://volcano.si.edu/volcano.cfm?vn=223030">Nyiragongo in the Democratic Republic of the Congo</a>. Most active volcanoes have craters filled with rocks and cooled lava, like <a href="https://www.usgs.gov/volcanoes/mount-st-helens/lava-flows-mount-st-helens">Mount St. Helens</a>, or with water, like <a href="https://www.usgs.gov/media/images/crater-lake-caldera-wizard-island-cinder-cone-and-lava-flows">Crater Lake in Oregon</a>. </p>
<p>The third problem is that dumping trash into those eight active lava lakes would be a very dangerous job. Lava lakes are covered with a crust of cooling lava, but just below that crust they are molten and intensely hot. If rocks or other materials fall onto the surface of a lava lake, they will break the crust, disrupt the underlying lava and cause an explosion. </p>
<p>This happened at Kilauea in 2015: Blocks of rock from the crater rim fell into the lava lake and caused a big explosion that <a href="https://www.usgs.gov/media/videos/rockfall-and-explosion-halemaumau-crater">ejected rocks and lava up and out of the crater</a>. Anyone who threw garbage into a lava lake would have to run away and dodge flaming garbage and lava.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/w8IaG2U65Is?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An eruption from the Cumbre Vieja volcano on the Spanish island of La Palma on Sept. 30, 2021, produced clouds of toxic gas.</span></figcaption>
</figure>
<p>Suppose it was possible to dump trash safely into a lava lake: What would happen to the trash? When plastics, garbage and metals burn, they release a lot of toxic gases. Volcanoes already give off tons of toxic gases, including sulfur, chlorine and carbon dioxide. </p>
<p>Sulfur gases can create acidic fog, which we call “vog,” for “volcanic fog.” It can <a href="https://www.usgs.gov/observatories/hawaiian-volcano-observatory/volcanic-gas">kill plants and cause breathing problems for people nearby</a>. Mixing these already-dangerous volcanic gases with other gases from burning our trash would make the resulting fumes even more harmful for <a href="https://www.usgs.gov/media/images/lava-breakouts-access_road">people and plants near the volcano</a>. </p>
<p>Finally, many indigenous communities view nearby volcanoes as sacred places. For example, Halema’uma’u crater at Kilauea is considered the home of Pele, the native Hawaiian goddess of fire, and the area around the crater is <a href="https://www.hawaii.com/discover/culture/pele/">sacred to native Hawaiians</a>. Throwing trash into volcanoes would be a huge insult to those cultures.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/170919/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Johnson receives funding from the U.S. Geological Survey </span></em></p>Volcanoes might seem like nature’s incinerators, but using them to burn up trash would be dangerous and disrespectful to indigenous people who view them as sacred.Emily Johnson, Research Geologist, US Geological SurveyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1694292021-10-07T18:33:17Z2021-10-07T18:33:17ZChang’e-5 samples reveal Moon rocks dating back less than 2 billion years – the youngest we’ve seen<figure><img src="https://images.theconversation.com/files/425218/original/file-20211007-19127-s7mg3a.jpg?ixlib=rb-1.1.0&rect=46%2C0%2C5184%2C3453&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/half-moon-background-astronomical-body-that-692162131">taffpixture/Shutterstock</a></span></figcaption></figure><p>Lava was still flowing on the surface of the Moon 1.97 billion years ago – and now we have the rocks to prove it. This is the result of new work from an international collaboration of planetary scientists, of which we’re a part, <a href="https://www.science.org/doi/10.1126/science.abl7957">published</a> in the journal Science.</p>
<p>Together with researchers from China, Australia, Sweden and the US, we’ve been studying samples collected from the Moon by the Chinese National Space Agency during the Chang’e-5 mission. </p>
<p>Chang'e-5 was an uncrewed mission including a robotic lander, which landed on the near side of the Moon (the Earth-facing side) in December 2020. The mission returned 1.7 kilograms of lunar rocks to Earth — the first samples collected from the Moon since 1976 with the Soviet Union’s <a href="https://solarsystem.nasa.gov/missions/luna-24/in-depth/">Luna 24 mission</a>.</p>
<p>A goal of the Chang'e-5 mission was to find evidence of some of the youngest volcanic eruptions on the Moon. Although scientists have previously been able to <a href="https://pubs.geoscienceworld.org/books/book/638/chapter/3806251/Ages-and-stratigraphy-of-lunar-mare-basalts-A">predict volcanic rocks</a> of this age on the Moon by studying the number of impact craters on the lunar surface, it is impossible to confirm this without having samples to examine.</p>
<p>Analysis of the samples took place using the sensitive high-resolution ion microprobe (Shrimp) instrument, at the Shrimp centre in Beijing, China. First, the material was sorted. Our colleagues in China manually picked out several tiny fragments of basalt (a volcanic rock), roughly 2 millimetres in size, for investigation. This was followed by laboratory analyses, building on techniques developed in the 1970s for the analysis of the first Apollo samples. </p>
<figure class="align-center ">
<img alt="The SHRIMP II instrument used for dating the basalt chips." src="https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/425108/original/file-20211006-23-m2raht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This SHRIMP II instrument was used for dating the basalt chips.</span>
<span class="attribution"><span class="source">Beijing SHRIMP Center, Institute of Geology, CAGS</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The process of determining the age of the rocks was complex, but in essence, we used a focused beam of charged particles to eject material from various mineral phases in the rocks and analysed the ejected material.</p>
<p>Our efforts were rewarded when we were able to determine an eruption age for these lavas of 1.97 billion years, a whole billion years younger than any previously dated basaltic lava from the Moon.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dramatic-change-in-the-moons-tilt-may-help-us-trace-the-origin-of-water-on-earth-56720">Dramatic change in the moon's tilt may help us trace the origin of water on Earth</a>
</strong>
</em>
</p>
<hr>
<h2>A new scientific mystery</h2>
<p>Many volcanic eruptions occurred on the Moon’s surface over its geological history, forming large sheets of basaltic rock, referred to as the <a href="https://www.britannica.com/science/mare-lunar-feature">lunar mare</a>. These can be seen as dark patches looking up at the Moon. </p>
<p>But most of the volcanic activity occurred between 3 and 4 billion years ago. Planetary scientists have confirmed this by <a href="https://www.sciencedirect.com/science/article/pii/S0016703719304661?via%3Dihub">dating basalts from the Apollo</a> and Luna rock collections, as well as meteorites that originated <a href="https://academic.oup.com/astrogeo/article/54/4/4.28/181834">from the Moon</a>. Until now though, younger volcanic rocks predicted by crater counting studies had remained elusive.</p>
<figure class="align-center ">
<img alt="The Chang’e-5 landing site, photographed by the lander." src="https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=324&fit=crop&dpr=1 600w, https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=324&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=324&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=407&fit=crop&dpr=1 754w, https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=407&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/425101/original/file-20211006-27-1wzsauy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=407&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chang'e-5 landed on the moon in December last year, and brought samples back to Earth.</span>
<span class="attribution"><span class="source">CNSA Lunar Exploration and Space Engineering Center</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In order for volcanic eruptions to occur, heat is required on the inside of a planet to generate the molten material involved in the process. For a planet the size of the Moon, it is thought that this heat would have been lost long before these eruptions 2 billion years ago. </p>
<p>This work has therefore opened up a new scientific mystery of how a small rocky planetary body like the Moon could have retained enough interior heat to continue producing volcanic eruptions 2.5 billion years after it first formed 4.5 billion years ago.</p>
<p>So what’s going on? While scientists have <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JE005742">previously suggested</a> that high concentrations of radioactive elements in the lunar interior could have melted rocky material inside the Moon, the compositions of these samples indicate this was not the driving force in this case. </p>
<p>It remains to be seen whether so-called <a href="https://link.springer.com/referenceworkentry/10.1007%2F1-4020-4520-4_408">tidal heating</a> could have played a role, where heat was generated in the Moon’s interior by the stretching and squeezing (think of an elastic band warming up through friction as you stretch it) due to gravity between the Moon, Earth and Sun. </p>
<p>Alternatively, it may be that a unique aspect of the Moon’s mantle composition could have resulted in a lower melting temperature, therefore explaining how the molten material was formed. Work is now continuing on the samples to try to shed light on this question. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-did-the-moon-end-up-where-it-is-114930">How did the moon end up where it is?</a>
</strong>
</em>
</p>
<hr>
<p>Analysing samples from the Apollo missions in the early 1970s revolutionised our understanding of how dynamic our Solar System is, and how planets form and evolve. Now, once more, this new study proves the <a href="https://link.springer.com/article/10.1007/s11214-019-0622-x">incredible scientific value</a> of returning samples from other planetary bodies to decode their secrets in laboratories on Earth. </p>
<p>Importantly, validating the crater counting approach with lunar samples also has key implications for dating the surfaces of other planets from which we haven’t yet collected samples (such as Mars, Venus and Mercury). It will enhance our understanding of the Solar System more broadly.</p><img src="https://counter.theconversation.com/content/169429/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joshua Snape receives funding from The Royal Society. </span></em></p><p class="fine-print"><em><span>Katherine Joy receives funding from The Royal Society, STFC and The Leverhulme Trust. </span></em></p><p class="fine-print"><em><span>Romain Tartese receives funding from STFC. </span></em></p>A key goal of the Chang'e-5 mission was to find evidence of some of the youngest volcanic eruptions on the Moon.Joshua Snape, Royal Society University Research Fellow, Department of Earth and Environmental Sciences, University of ManchesterKatherine Joy, Royal Society University Research Fellow / Reader, School of Earth and Environmental Sciences, University of ManchesterRomain Tartese, Senior Research Fellow, Department of Earth and Environmental Sciences, University of ManchesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1619902021-06-04T08:07:32Z2021-06-04T08:07:32ZThe eruption of Mount Nyiragongo: its health effects will be felt for a long time<figure><img src="https://images.theconversation.com/files/404031/original/file-20210602-25-1b0yqo2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Men cross the front of the still smoking lava rocks from an eruption of the Mount Nyiragongo on May 23, 2021 in Goma in the east of the Democratic Republic of Congo. </span> <span class="attribution"><span class="source">GUERCHOM NDEBO/AFP via Getty Images</span></span></figcaption></figure><p><em>The eruption of Mount Nyiragongo, an active volcano in the Democratic Republic of the Congo (DRC), <a href="https://www.bbc.com/news/world-africa-57228666">led to</a> the deaths of
at least 30 people. There could however be longer term health implications for residents of the area. Patrick DMC Katoto, who has studied the health effects of volcanoes in the DRC, provides insights into the health risks that a volcanic eruption brings.</em></p>
<hr>
<h2>What are the main health concerns for communities?</h2>
<p>Volcanic eruptions can cause catastrophic destruction. They are responsible for human casualties, infrastructural devastation and can pollute the environment for thousands of kilometers around the eruption sites. </p>
<p>There are various attributes that a volcano has that makes it dangerous to human health. During the eruption, lava, gas and volcanic ash are released. The eruption can also cause, or lead to, earth tremors and quakes. </p>
<p>The hot lava that erupts from a volcano is lethal. It can move fast and directly cause death or injury. It can also destroy homes and other important structures including electricity and petrol stations (risking massive explosions) and water tanks. </p>
<p>Nyiragongo is considered one of the most dangerous volcanoes in the world because of its particularly fast-moving lava. It can flow at a speed of <a href="https://www.pbs.org/wgbh/nova/volcanocity/anat-nf.html">about</a> 100km per hour. It’s reported that, in this recent eruption, <a href="https://www.bbc.com/news/world-africa-57228666">about</a> 30 people died when more than 500 houses were flattened by the lava flow. Because of the devastation, there could be mental health challenges for the people affected. </p>
<p>Volcanic ash – <a href="https://pubs.usgs.gov/fs/fs027-00/#:%7E:text=Ash%20Fall%E2%80%94A%20%22Hard%20Rain,Particles%20%7C%20USGS%20Volcano%20Fact%20Sheet&text=Volcanic%20ash%20consists%20of%20tiny,the%20air%20by%20a%20volcano.">composed of</a> tiny particles of rocks, minerals, and volcanic glass – is a major health concern. When inhaled it can cause lung damage, for instance one long-term effect of volcanic ash is <a href="https://serc.carleton.edu/NAGTWorkshops/health/case_studies/volcanic_ash.html#:%7E:text=Inhalation%20of%20volcanic%20ash%20can,eye%20problems%2C%20and%20skin%20irritiation.&text=One%20long%2Dterm%20effect%20of%20volcanic%20ash%20is%20silicosis.">silicosis</a> a disease that can cause lung impairment and scarring. Inhaling volcanic ash can also cause suffocation, leading to death. </p>
<p>In addition, volcanic ash contains strong acids, such as hydrogen fluoride and hydrochloric acid. In small concentrations they can cause skin irritation and eye problems.</p>
<p>If the volcanic ash were to land in natural water sources, it would deposit <a href="https://volcanoes.usgs.gov/volcanic_ash/water_supply.html">toxic minerals</a>. If ingested these can cause neurological disorders.</p>
<p>Ash can also <a href="https://serc.carleton.edu/NAGTWorkshops/health/case_studies/volcanic_ash.html">trap</a> toxic gases in the atmosphere, such as carbon dioxide and fluorine. This <a href="https://www.ivhhn.org/information/health-impacts-volcanic-gases">can affect</a> crops or lead to animal and human illness or death. </p>
<p>Alongside the ash and lava, volcanic eruptions release toxic gases. </p>
<p>Mount Nyiragongo is one of the most prolific sources of sulphur dioxide on earth. Since September 2002, this volcano has had a permanent lava lake which <a href="http://digital.casalini.it/10.1400/19080">persistently releases</a> a plume of gases rich in sulphur dioxide and carbon. It therefore produces suplhur dioxide during and after eruption.</p>
<p>Sulphur dioxide can irritate the skin and the tissues and mucous membranes of the eyes, nose, and throat. It <a href="https://www.ivhhn.org/information/health-impacts-volcanic-gases">can also</a> aggravate chronic conditions including asthma and cardiovascular diseases. </p>
<p>During, and sometimes after, eruption another concern are earthquakes and tremors. It has <a href="https://edition.cnn.com/2021/05/30/africa/drc-volcano-tremors-intl/index.html">been reported</a> that up to 92 earthquakes and tremors were detected in the days following the eruption.</p>
<p>Aside from the risk of potential building collapses, there’s <a href="https://www.bbc.com/news/world-africa-57280509">concern</a> that these tremors could affect Lake Kivu, just 12km away, which has large amounts of methane and carbon dioxide dissolved in its deep waters. If disturbed <a href="https://theconversation.com/why-exploring-for-oil-under-lake-kivu-carries-unique-and-huge-risks-78107">they could</a> come to the surface and erupt. The explosion could be catastrophic to surrounding communities. The gas that’s released would also be toxic and could cause suffocation. </p>
<p>It’s important to bear in mind that some health issues won’t be directly related to the volcano, but can arise because of the event. </p>
<p>For instance, water treatment structures have <a href="https://www.msf.org/half-million-without-drinking-water-following-drc-volcano-eruption">been damaged</a>. It’s estimated that <a href="https://www.msf.org/half-million-without-drinking-water-following-drc-volcano-eruption">over</a> 500,000 people in Goma have been left without access to clean drinking water. This could lead to outbreaks of water-borne illness, such as <a href="https://apps.who.int/disasters/repo/7828.pdf">cholera</a>.</p>
<h2>How long do these health concerns last?</h2>
<p>We <a href="https://ehjournal.biomedcentral.com/articles/10.1186/s12940-020-00615-9">recently published a study</a> on the effects of continuous exposure to sulphur dioxide among people living in Goma. Our data covered a 10 year period and was collected from health centres around the Nyiragongo and Nyamulagira volcanoes. We found clear evidence between the increased incidence of acute respiratory symptoms following eruptions, particularly in areas near volcanoes (26km) up to six months following the eruption.</p>
<p>This shows that ongoing exposure to harmful gas and particles in the air could continue to affect residents months after the event.</p>
<p>Returning to normal will take a long time. The eruption has happened in a place which <a href="https://www.dw.com/en/surge-in-violence-exacerbates-congo-humanitarian-crisis/av-57443728">already faces</a> a humanitarian crises with a high rate of violence in the region. In addition to this, the health system is already fragile. It’s had to battle a recent <a href="https://www.msf.org/drc-ebola-outbreak-crisis-update">Ebola virus outbreak</a> and is now grappling to deal with the COVID-19 pandemic. </p>
<p>Returning to normal will necessitate a global and coordinated response in which humanitarians, other states and the DRC combine efforts. </p>
<h2>What actions must policymakers take to protect people?</h2>
<p>In terms of immediate steps, policymakers should put their efforts into the provision of emergency food supplies and chlorinated water. They should also prepare for the outbreak of diseases, such as cholera by putting in place a health surveillance system in health centres and shelters. This surveillance should also capture respiratory diseases and all COVID-19 related symptoms. </p>
<p>In addition, there must be services on hand to support the mental health of those affected by the eruption. </p>
<p>To protect themselves <a href="https://www.ivhhn.org/ash-protection">from ash</a>, a well-fitting, industry-certified facemask – such as an N95 mask – will provide some respiratory protection. Surgical masks (although effective in the fight against COVID-19 infection) protect little against the particles present in volcano fumes, but it’s better than nothing. </p>
<p>A real time monitoring system for ash and gases is needed to track air quality. Unfortunately, there isn’t much people can do protect themselves aside from moving away – especially children, elders and people with asthma. If possible, people must stay inside a well-insulated house (doors and windows closed) or wear a gas mask (rarely available) outdoors. This will be an additional health challenge given the current COVID-19 pandemic if not well addressed. </p>
<p><em>Jonathan Koko Byamungu, from the Department of Chemical Engineering at the University of KwaZulu Natal, contributed to this interview.</em></p><img src="https://counter.theconversation.com/content/161990/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patrick de Marie C. Katoto does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Nyiragongo is one of the most dangerous volcanoes in the world because of its fast-moving lava. It can flow at a speed of about 100km per hour.Patrick de Marie C. Katoto, Lecturer, Université catholique de BukavuLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1618472021-05-31T17:24:36Z2021-05-31T17:24:36ZMount Nyiragongo’s volcano: why it’s unique and treacherous<figure><img src="https://images.theconversation.com/files/403611/original/file-20210531-23-tqhdyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Still standing: a structure surrounded by lava following a volcanic eruption on 23 May 2021 in Goma, a city in eastern Democratic Republic of Congo. </span> <span class="attribution"><span class="source">Moses Sawasawa via GettyImages</span></span></figcaption></figure><p><em>Seismologists in the Democratic Republic of Congo (DRC) were <a href="https://edition.cnn.com/videos/world/2021/05/31/drc-congo-goma-mount-nyiragongo-madowo-lkl-intl-hnk-vpx.cnn">still reporting earthquakes</a> around the Mount Nyiragongo volcano a week after it erupted. The original eruption <a href="https://www.washingtonpost.com/world/residents-search-for-dead-killed-by-congos-volcano-eruption/2021/05/24/196b70b6-bca5-11eb-922a-c40c9774bc48_story.html">killed at least 32 people</a> and tens of thousands had to flee the area. The Conversation Africa’s Moina Spooner asked earth scientist Paolo Papale to explain the particular conditions in the Virunga volcanic chain, and what makes it particularly dangerous.</em></p>
<h2>What makes this volcano particularly dangerous?</h2>
<p>Mount Nyiragongo is part of the Virunga volcanic chain, and owes its existence to the activity of the <a href="https://theconversation.com/africa-is-splitting-in-two-here-is-why-94056">African Great Rift</a>. The rift is constantly extending and opening. In a few tens of million years it will have led to the creation of a new ocean separating the bulk of the African continent from its present eastern portion. </p>
<p>We can see what the future would look like by observing present-day <a href="https://africa-arabia-plate.weebly.com/madagascar-plate.html">Madagascar</a>, which was once attached to continental Africa. </p>
<p>The peculiar location of Mount Nyiragongo on a highly active segment of the African rift favours quick ascent of magma (molten material) from about 100 km beneath the Earth’s surface, and extreme fluidity of lava. That is one major reason of concern, as the lava flowing on the upper volcano flanks can be extremely fast and impossible to escape.</p>
<p>The <a href="https://earthobservatory.nasa.gov/images/9160/nyiragongo-volcano-erupts-in-the-congo">eruption of 2002 </a>was caused by a sudden episode of rift opening. Estimates were that 100 people had died and <a href="https://www.bbc.co.uk/bitesize/guides/zpf9mnb/revision/7">up to hundreds of thousands were forced to flee</a> from the town of Goma and from the villages on the upper volcano flanks. </p>
<p>About 16km of fractures formed from the summit towards Goma and lava poured out from several locations along it, including from the outskirts of Goma. The Nyiragongo lava flowing from vents at lower altitude tends to be more viscous and slower. It gives people time to escape, but its stickiness is also more destructive to buildings in its path. </p>
<p>This time the fractures and vents weren’t at such a low altitude. The lava hasn’t reached the city yet. </p>
<p>Other dangers associated with rifting, and volcano activity in the region, are: </p>
<ul>
<li>the earthquakes accompanying rifting episodes, which can themselves cause significant damage.<br></li>
</ul>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1397193474471043083"}"></div></p>
<ul>
<li><p>explosions when the hot lava reaches <a href="https://theconversation.com/why-exploring-for-oil-under-lake-kivu-carries-unique-and-huge-risks-78107">Lake Kivu</a> waters causing its sudden boiling; </p></li>
<li><p>the release of carbon-rich gases, particularly methane, during rifting and eruption, leading to explosions; </p></li>
<li><p>the potential for carbon-rich gas accumulation at the bottom of lake Kivu, which may cause surface water to sink, releasing lethal gases threatening Goma.</p></li>
</ul>
<h2>How well did the government cope? Was it better than 2002?</h2>
<p>Before and during the 2002 eruption the Goma Volcano Observatory did an excellent job with few resources, in terms of instruments and funds. In spite of having only three very old seismometers recording on paper, <a href="https://www.nature.com/news/2002/020121/full/news020121-11.html">they were able to raise the alarm </a> that the volcano was about to re-awaken days before the eruption occurred on January 17. </p>
<p>Unfortunately, the political situation at the time wasn’t favourable. Rwandan military forces were occupying the area and a local government was in place that had a complex relationship with the national government in Kinshasa. The alarms by the volcanologists remained unheard. The <a href="https://news.un.org/en/story/2002/01/26422-un-mission-spends-700000-volcano-relief-effort-dr-congo">result</a> was that hundreds of thousands of people fled across the Congo-Rwanda border and nearly as many found themselves homeless after the volcano erupted. </p>
<p>The crisis was then managed by the <a href="https://www.un.org/press/en/2002/sgsm8104.doc.htm">United Nations</a>. Days after the eruption it sent the first group of international scientists to the site. It then maintained a year-long programme of international cooperation involving Congolese volcanologists. </p>
<p>The eruption in 2002 triggered substantial <a href="https://reliefweb.int/report/democratic-republic-congo/human-health-and-vulnerability-nyiragongo-volcano-crisis-dr-congo">international support</a> and many scientific papers. Some warned about the danger of rebuilding the city along the 2002 eastern lava flow originating close to the Munigi village. They suggested measures to protect the city against future lava flows. </p>
<p>As far as I am aware, this advice wasn’t followed. The city was rebuilt above the 2002 lava flows and expanded to <a href="https://www.macrotrends.net/cities/205453/goma/population">four times</a>.</p>
<h2>What must be done to protect communities?</h2>
<p>The social and political conditions in Eastern Congo are extremely difficult.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/violence-is-endemic-in-eastern-congo-what-drives-it-156039">Violence is endemic in eastern Congo: what drives it</a>
</strong>
</em>
</p>
<hr>
<p>Still, the communities in and around Goma must be protected from the volcano; the humanitarian disruption from hundreds of thousands of homeless people must be prevented; and the political instabilities following massive and uncontrolled country border crossing must be avoided. </p>
<p>The rifting process and the eruption of magma can’t be controlled. Under such conditions, one should either relocate the town, which would be extremely difficult for a town the size of Goma (which also has a strategic location and political relevance), or at least reduce the risk to controlled levels. </p>
<p>Following the 2002 eruption we at the <a href="http://www.pi.ingv.it/">National Institute of Geophysics and Volcanology</a> in Pisa, Italy, started a programme of hazard evaluation and risk mitigation from lava flow invasion in Goma. We used numerical simulations of lava flow invasion to identify and characterise the most efficient and effective artificial barriers that would maximise shielding and protection in town. </p>
<p>It is clear, however, that the local and national governments need to be more aware of the risks from tectonic rifting and from the volcano. </p>
<p><em>The article has been updated to remove any misunderstanding about the Goma Observatory, the Royal Museum for Central Africa, the European Center for Geodynamics and Seismology and the National Museum of Natural History of Luxembourg as well as any ambiguity about the seismicity warning systems that are in place.</em></p><img src="https://counter.theconversation.com/content/161847/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paolo Papale receives funding from the European Commission. He also managed funds from the Italian Civil Protection Department during his time as the Head of the National Program on Volcanic Hazards. He was part of a group of scientists sent to the DRC by the UN after the eruption in 2002 to support the Goma Volcano Observatory.</span></em></p>National governments need to wake up to the volcanic risks posed by tectonic rifting around Mount Nyiragongo.Paolo Papale, Director of Research , Istituto Nazionale di Geofisica e Vulcanologia (INGV)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1484042020-11-02T20:01:34Z2020-11-02T20:01:34ZMagnetism of Himalayan rocks reveals the mountains’ complex tectonic history<figure><img src="https://images.theconversation.com/files/365671/original/file-20201026-17-199ct3j.jpg?ixlib=rb-1.1.0&rect=155%2C0%2C2993%2C1999&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Himalayan rocks hold magnetic clues about their origins.</span> <span class="attribution"><span class="source">Craig Robert Martin</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Breathing quickly in the thin mountain air, my colleagues and I set down our equipment. We’re at the base of a jagged outcrop that protrudes upwards out of a steep gravel slope.</p>
<p>The muffled soundscape of the spectacular Himalayan wilderness is punctuated by a military convoy roaring along the Khardung-La road below. It’s a reminder how close we are to the long-disputed borders between India, Pakistan and China which lie on the ridgelines just a few miles away.</p>
<iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d13088582.506864522!2d68.70515675564154!3d34.45999998049693!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x0%3A0x0!2zMzTCsDI3JzM2LjAiTiA3N8KwNDAnMTIuMCJF!5e1!3m2!1sen!2sus!4v1604077003054!5m2!1sen!2sus" width="100%" height="450" frameborder="0" style="border:0;" allowfullscreen="" aria-hidden="false" tabindex="0"></iframe>
<p>This area also contains a different type of boundary, a narrow sinuous geological structure that stretches along the length of the Himalayan mountain range. Known as a suture zone, it’s only a few kilometers wide and consists of slivers of different types of rocks all sliced together by fault zones. It marks the boundary where two tectonic plates fused together and an ancient ocean disappeared.</p>
<p>Our team of geologists traveled here to collect rocks that erupted as lava more than 60 million years ago. By decoding the magnetic records preserved inside them, we hoped to reconstruct the geography of ancient landmasses – and <a href="https://doi.org/10.1073/pnas.2009039117">revise the story of the creation of the Himalayas</a>.</p>
<h2>Sliding plates, growing mountains</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="artist's rendering of two tectonic plates colliding at a subduction zone" src="https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=489&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=489&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=489&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=614&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=614&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366741/original/file-20201030-23-t6znxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=614&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">At a subduction zone, two tectonic plates collide, with one slowly sliding beneath the other.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/tectonic-plates-world-map-royalty-free-illustration/889618718">VectorMine/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Tectonic plates make up the surface of Earth, and they’re constantly in motion – drifting at the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/tectonic-plate">imperceptibly slow pace</a> of just a few centimeters each year. Oceanic plates are colder and denser than the mantle beneath them, so they sink downward into it at subduction zones.</p>
<p>The sinking edge of the ocean plate drags the ocean floor along behind it like a conveyor belt, pulling the continents toward each other. When the entire ocean plate disappears into <a href="https://www.nationalgeographic.org/encyclopedia/mantle/">the mantle</a>, the continents on either side plow into each other with enough force to uplift great mountain belts, like the Himalayas.</p>
<p>Geologists generally thought that the Himalayas formed <a href="https://doi.org/10.1130/0016-7606(2000)112%3C324:TOTHAS%3E2.0.CO;2">55 million years ago in a single continental collision</a> – when the Neotethys Ocean plate subducted under the southern edge of Eurasia and the Indian and Eurasian tectonic plates collided. </p>
<p>But by measuring the magnetism of rocks from northwest India’s remote and mountainous Ladakh region, our team has shown that the tectonic collision that formed the world’s largest mountain range was actually a complex, multi-stage process involving at least two subduction zones.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="diagram of interior of Earth and magnetic field stretching from pole to pole" src="https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=646&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=646&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=646&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=811&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=811&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366500/original/file-20201029-13-1784e5k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=811&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earth’s magnetic field is generated by movement within the planet’s outer core. Magnetic north and south drift and sometimes flip over time.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/earth-magnetic-field-scientific-vector-royalty-free-illustration/932342344">VectorMine/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Magnetic messages, preserved for all time</h2>
<p>Constant movement of our planet’s metallic outer core creates electric currents which in turn generate <a href="https://cosmosmagazine.com/geoscience/what-creates-earth-s-magnetic-field/">Earth’s magnetic field</a>. It’s oriented differently depending where in the world you are. The magnetic field always points toward the magnetic north or the south, which is why your compass works, and averaged over thousands of years it points toward the geographic pole. But it also slopes downward into the ground at an angle which varies depending on how far you are from the equator. </p>
<p>When lava erupts and cools to form rock, the magnetic minerals inside lock in the direction of the magnetic field of that location. So <a href="https://doi.org/10.1016/B0-12-369396-9/00106-4">by measuring the magnetization of volcanic rocks</a>, <a href="https://scholar.google.com/citations?hl=en&user=aD8WioMAAAAJ">scientists like me</a> can determine what latitude they came from. Essentially, this method allows us to unwind millions of years of plate tectonic motions and create maps of the world at different times throughout geologic history.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Member of our research team collecting samples in Ladakh." src="https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=884&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=884&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=884&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1111&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1111&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365226/original/file-20201023-20-172l0hn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1111&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Geologist collects core samples using a water-cooled electric core drill.</span>
<span class="attribution"><span class="source">Craig Robert Martin</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Over multiple expeditions to the Ladakh Himalayas, our team collected hundreds of 1-inch diameter rock core samples. These rocks originally formed on a volcano active between 66 and 61 million years ago, around the time that the first stages of collision began. We used a hand-held electric drill with a specially designed diamond coring bit to drill approximately 10 centimeters down into the bedrock. We then carefully marked these cylindrical cores with their original orientation before chiseling them out of the rock with nonmagnetic tools.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="cylindrical rock core samples with markings" src="https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=431&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=431&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=431&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=542&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=542&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366238/original/file-20201028-15-ujjeor.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=542&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A few rock core samples, with the sample orientation line marked on their sides.</span>
<span class="attribution"><span class="source">Craig Robert Martin</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The aim was to reconstruct where these rocks originally formed, before they were sandwiched between India and Eurasia and uplifted into the high Himalayas. Keeping track of the orientation of the samples as well as the rock layers they came from is essential to calculating which way the ancient magnetic field pointed relative to the surface of the ground as it was over 60 million years ago.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="View of magnetometer equipment at MIT." src="https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365268/original/file-20201023-19-1igxsu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The magnetometer sits inside a magnetically shielded room at the MIT Paleomagnetism Laboratory.</span>
<span class="attribution"><span class="source">Craig Robert Martin</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>We brought our samples back to the <a href="http://www.benweiss.mit.edu/">MIT Paleomagnetism Laboratory</a> and, inside a special room that’s shielded from the modern-day magnetic field, we heated them in increments up to 1,256 degrees Fahrenheit (680 degrees Celsius) to slowly remove the magnetization.</p>
<p>Different mineral populations acquire their magnetization at different temperatures. Incrementally heating and then measuring the samples in this way enables us to extract the original magnetic direction by removing more recent overprints that might hide it.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="diagrams depicting India colliding with Eurasia either in a single stage or multiple stages" src="https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=239&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=239&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=239&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=301&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=301&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366244/original/file-20201028-17-hpwmb7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=301&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Black lines mark boundaries between tectonic plates. Black lines with triangular tick marks show subduction zones, with the direction of subduction. The Trans-Tethyan Subduction Zone is the additional subduction zone not accounted for in the single-stage collision model. The Trans-Tethyan Subduction Zone is where the volcanic island chain formed before the Indian continent collided into it and pushed it into Eurasia, forming the Himalaya.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1073/pnas.2009039117">Martin et al 'Paleocene latitude of the Kohistan-Ladakh arc indicates multi-stage India-Eurasia collision,' PNAS 2020</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<h2>Magnetic traces build a map</h2>
<p>Using the average magnetic direction of the whole suite of samples we can calculate their ancient latitude, which we refer to as the paleolatitude.</p>
<p>The original single-stage collision model for the Himalaya predicts that these rocks would have formed close to Eurasia at a latitude of around 20 degrees north, but our data shows that these rocks did not form on either the Indian or the Eurasian continents. Instead, they formed on a chain of volcanic islands, out in the open Neotethys Ocean at a latitude of about 8 degrees north, thousands of kilometers south of where Eurasia was located at the time.</p>
<p>This finding can be explained only if there were <a href="https://doi.org/10.1038/ngeo2418">two subduction zones</a> pulling India rapidly toward Eurasia, rather than just one. </p>
<p>[<em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklysmart">You can get our highlights each weekend</a>.]</p>
<p>During a geologic time period known as the Paleocene, India caught up with the volcanic island chain and collided with it, scraping up the rocks we eventually sampled onto the northern edge of India. India then continued northward before <a href="https://doi.org/10.1016/j.epsl.2013.01.023">ramming into Eurasia around 40 to 45 million years ago</a> – 10 to 15 million years later than was generally thought.</p>
<p>This final continental collision raised the volcanic islands from sea level up over 4,000 meters to their present-day location, where they form jagged outcrops along a spectacular Himalayan mountain pass.</p><img src="https://counter.theconversation.com/content/148404/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Craig Robert Martin receives funding from the National Science Foundation (NSF).</span></em></p>Earth’s magnetic field locks information into lava as it cools into rock. Millions of years later, scientists can decipher this magnetic data to build geologic timelines and maps.Craig Robert Martin, Ph.D. Student in Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1164292019-06-11T00:20:48Z2019-06-11T00:20:48ZCurious Kids: where do rocks come from?<figure><img src="https://images.theconversation.com/files/276702/original/file-20190528-92790-1ehkdqf.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5463%2C2506&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rocks contain a layer-by-layer record of the history of our planet.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/86755183@N04/16485047966/">Fred Moore/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Where do rocks come from? - Claire, age 5, Perth, WA.</strong></p>
</blockquote>
<p>Wow, Claire, what a great question. Sitting in a university, I rarely get asked such brilliant questions. So, thank you. </p>
<p>As strange as it sounds, rocks are made from stardust; dust blasted out and made from exploding stars. </p>
<p>In fact, our corner of space has many rocks floating around in it. From really fine dust, to pebbles, boulders and house-sized rocks that can burn up in the night sky to make meteors or “shooting stars”. </p>
<p>The Moon and our local planets – Mars, Venus and Mercury – are just the largest rocks floating around our part of space. These are all made from space dust stuck together over billions of years.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-was-the-earth-made-112067">Curious Kids: how was the Earth made?</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277790/original/file-20190604-69079-tznyh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An artist’s impression of early Earth, which was then a molten ball of lava flying through space.</span>
<span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA15808">NASA/JPL-Caltech</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>The ‘light’ rocks are on the Earth’s surface</h2>
<p>Planet Earth is a rock too, but so much has happened since it was formed from dust and small rocks that smashed and stuck together 4.543 billion years ago.</p>
<p>As the space dust hit each other to make the earth, it got super hot and melted. The Earth was, at that time, a spinning ball of red-hot lava flying through space. </p>
<p>In this melted lava planet, heavy bits of the earth sank and the light frothy bits gathered on the surface. </p>
<p>Have you ever looked closely at a glass of milky coffee at a cafe? The dark heavy coffee is at the bottom, whereas the light, frothy milk sits on the top. Well, our planet was a bit like that coffee billions of years ago. </p>
<iframe src="https://giphy.com/embed/fEZ982FPO0jIc" width="100%" height="480" frameborder="0" class="giphy-embed" allowfullscreen=""></iframe>
<p><a href="https://giphy.com/gifs/eastbay-fEZ982FPO0jIc"></a></p>
<p>We don’t see the really heavy rocks these days because they sank deep in the planet very early on. The rocks we see on the surface are like the frothy milk! They were light and rose to the top. Then, as time moved on, the planet cooled and froze to become the solid earth we have now. </p>
<p>I know most rocks are heavy. But in fact some rocks – even really big ones like Uluru – are actually much lighter than the rocks found in the deep Earth.</p>
<h2>Lava and plates</h2>
<p>Those rocks on the Earth’s surface actually <a href="https://theconversation.com/a-map-that-fills-a-500-million-year-gap-in-earths-history-79838">move around</a>. Large chunks the size of continents (called “plates”) jostle each other and this can cause earthquakes. Some of them get forced under other plates and heat up and eventually melt. This forms more lava. The lava erupts from volcanoes, then cools and forms new rocks. </p>
<p>Here are some pictures of lava in the melted state and then after it has cooled down:</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/276748/original/file-20190528-42560-rvs752.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Volcanic lava in Etra Ale Volcano in Ethiopia in 2016. Lava emerges from volcanoes and then cools on the Earth’s surface to form rocks.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/myneur/6900576021/">Petr Meissner/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-mountains-form-108246">Curious Kids: how do mountains form?</a>
</strong>
</em>
</p>
<hr>
<h2>Mountains and gems are also rocks</h2>
<p>Mountains form where two plates smash into each other. The rocks that get caught between two of the Earth’s plates get squashed under huge pressures and heat up. These can form really beautiful rocks. Sometimes gems form in these rocks and people try to find them to make jewellery.</p>
<p>Rain and ice break up the rocks in mountains. These form sand and mud that get washed out to form beaches, rivers and swamps. This sand and mud can get buried, squashed and heated, which eventually turns them into rocks.</p>
<p>Rocks contain a record of the history of our planet; what is has been through and what is capable of. We are only just learning how to read it. </p>
<p>So, next time you see a rock, just think what an incredible story it contains.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273473/original/file-20190509-183086-sm9qf0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spectacular layered sedimentary rocks from Tigray, Ethiopia, where each layer represents an ancient sea bed. Rocks of these types contain the history of the surface of the planet.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Alan Collins receives funding from a number of industry and government sources including the Australian Research Council</span></em></p>As strange as it sounds, rocks are made from stardust.Alan Collins, Professor of Geology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/982512018-07-22T20:09:28Z2018-07-22T20:09:28ZCurious Kids: Why do volcanoes erupt?<figure><img src="https://images.theconversation.com/files/223750/original/file-20180619-126537-gka5w8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some explosive volcanoes can send ash high up into the sky and it can travel around the world over different countries.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com">Shutterstock</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em></p>
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<p><strong>Why do volcanoes erupt? - Nicholas, age 3 years and 11 months, Northmead, NSW.</strong> </p>
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<p>The rock inside the planet we live on can melt to form molten rock called magma. This magma is lighter than the rocks around it and so it rises upwards. Where the magma eventually reaches the surface we get an eruption and volcanoes form. </p>
<p>The top part of the Earth is made up of a number of hard pieces called tectonic plates. Magma and volcanoes often form where the plates are pulled apart or pushed together but we also find some volcanoes in the middle of tectonic plates.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-why-doesnt-lava-melt-the-side-of-the-volcano-90683">Curious Kids: why doesn't lava melt the side of the volcano?</a>
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<p>Volcanoes have many different shapes and sizes, some look like steep mountains (stratovolcanoes), others look like bumps (shield volcanoes) and some are flat with a hole (a crater or caldera) in the centre that is often filled with water.</p>
<p>The shape of the volcano and how explosively it erupts depend largely on how “sticky” and how “fizzy” (how much gas) the magma is that is erupted. </p>
<p>For example, if you try to blow bubbles in cooking oil though a straw, the bubbles can escape quite easily because the cooking oil is runny.</p>
<p>If you try to blow bubbles in jam or peanut butter you would find it very difficult because the jam and peanut butter are very sticky, they wouldn’t move much at all if you tried to pour them out of the jar.</p>
<p>It is the same with volcanoes. When magma rises towards the surface gas bubbles start to form. Whether or not they can escape as the magma is rising affects how explosive the eruption will be.</p>
<p>Where the magma is runny like cooking oil and doesn’t have much bubbly gas mixed in it, such as places like Hawaii, then we see lots of slow-moving lava flows and shield volcanoes. Lava is what we call magma when it reaches the surface.</p>
<p>Here are some pictures of a recent Hawaiian eruption:</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1001626626273103872"}"></div></p>
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<p>However, where the magma is very sticky, like jam or peanut butter, and if it contains a lot of bubbly gas then the gas can get stuck and eruptions can be very powerful and explosive, like the recent eruptions at Fuego volcano in Guatemala.</p>
<h2>Damage caused by eruptions</h2>
<p>In explosive eruptions the frothy, bubbly magma can be ripped apart into tiny bits called volcanic ash. This is not ash like you get after a barbecue or fire, it does not crumble away in your fingers. It is very sharp and is dangerous to breathe in.</p>
<p>Some explosive volcanoes can send ash high up into the sky and it can travel around the world over different countries. If aeroplanes travel through an ash cloud from a volcano it can cause a lot of damage to the engine.</p>
<p>Other explosive eruptions create fast-moving, hot clouds of volcanic ash, gas and rocks that travel down the sides of the volcanoes and destroy pretty much everything in their path.</p>
<h2>The benefits of volcanoes</h2>
<p>Despite the great damage they can cause, volcanoes also help us to live. Volcanic ash provides food for the soil around volcanoes which helps us grow plants to eat. The heat from some volcanoes is used to make energy to power lights, fridges, televisions and computers in people’s houses. </p>
<p>You can find some more information about different types of volcanoes <a href="https://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/Types-of-Volcanoes-Eruptions">here</a> and <a href="http://www.bgs.ac.uk/discoveringGeology/hazards/volcanoes/types.html">here</a>. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-do-most-volcanologists-die-from-getting-too-close-to-volcanoes-82496">Curious Kids: Do most volcanologists die from getting too close to volcanoes?</a>
</strong>
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<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p><em>Please tell us your name, age, and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/98251/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Handley receives funding from the Australian Research Council. She is affiliated with WOMEESA.</span></em></p>When magma rises towards the surface gas bubbles start to form. Whether or not they can escape as the magma is rising affects how explosive the eruption will be.Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/977752018-06-06T00:43:13Z2018-06-06T00:43:13ZFrom Kilauea to Fuego: three things you should know about volcano risk<p>Recent photographs and video from the <a href="https://theconversation.com/fuego-volcano-the-deadly-pyroclastic-flows-that-have-killed-dozens-in-guatemala-97707">devastating eruption</a> of Fuego volcano in Guatemala show people stood watching and filming hot, cloud-like flows of gas, ash and volcanic material (known as <a href="https://volcanoes.usgs.gov/vhp/pyroclastic_flows.html">pyroclastic flows</a>) travelling towards them down the slopes of the volcano. </p>
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<p>From this it is clear that some people do not fully understand the risks of the volcanoes they live near. </p>
<p>Although <a href="https://www.britannica.com/science/volcano">each volcano is different</a>, and each presents different risks to the people near to them, there are some generalisations that help us understand what these risks are likely to be.</p>
<p>Three points are clear: location matters, explosiveness can be predicted to an extent, and fast-moving pyroclastic flows of volcanic material are deadly. </p>
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Read more:
<a href="https://theconversation.com/fuego-volcano-the-deadly-pyroclastic-flows-that-have-killed-dozens-in-guatemala-97707">Fuego volcano: the deadly pyroclastic flows that have killed dozens in Guatemala</a>
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<h2>1. Location matters</h2>
<p>The outer layer of the Earth, called the <a href="https://www.nationalgeographic.org/encyclopedia/lithosphere/">lithosphere</a> (crust and upper mantle), is broken up into a number of rigid tectonic plates. <a href="http://geologylearn.blogspot.com/2016/03/relation-of-volcanism-to-plate-tectonics.html">Volcanoes typically occur</a> where the plates move apart from one another, for example at underwater mid-ocean ridges, or collide together at subduction zones. </p>
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<a href="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Australia sits in the middle of a tectonic plate - whereas New Zealand sits on a boundary between two tectonic plates. <strong>CLICK ON IMAGE TO ZOOM</strong></span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/plate-tectonics-earths-lithosphere-scientific-theory-134705048?src=tTw-S8Bbu7hIuslxFGjmZg-1-4">from www.shutterstock.com</a></span>
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<p>We also find volcanoes in the middle of tectonic plates – these are called “intraplate” volcanoes, such as the Hawaiian and Galápagos oceanic islands. </p>
<p>The magma (molten rock) that feeds volcanoes is generated in different ways in these settings, and different volcanic landforms result. </p>
<p>Hawaii is in the middle of a tectonic plate and volcanic activity there forms relatively low-profile, <a href="https://volcano.si.edu/learn_galleries.cfm?p=2">shield volcanoes</a>. Typically, these volcanoes are built up by many fluid lava flows into broad, gently sloping domes, which resemble a warrior’s shield.</p>
<p>In contrast, Fuego is situated in a subduction zone environment (one plate going under another) where steep-sided, <a href="http://volcano.oregonstate.edu/stratovolcanoes">stratovolcanoes, or composite</a> volcanoes are most common. These often symmetrical, conical volcanoes form from the build up of layers of lava and pyroclastic (fragmented volcanic) rocks.</p>
<h2>2. Magma and gas affect explosiveness</h2>
<p>The volcanic landforms and eruptive styles we see in different settings are largely a <a href="http://www.geology.sdsu.edu/how_volcanoes_work/Controls.html">result of the differences</a> in the composition of the magma (molten rock) erupted, its temperature and its gas content in these contrasting tectonic settings.</p>
<p>Large shield volcanoes in the middle of tectonic plates, such as <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/geo_hist_2008.html">Kilauea volcano in Hawaii</a>, erupts high temperature, low silica lava. This is runnier (less viscous) than magma typically erupted at subduction zone volcanoes (like Fuego). </p>
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Read more:
<a href="https://theconversation.com/eruptions-and-lava-flows-on-kilauea-but-whats-going-on-beneath-hawaiis-volcano-96919">Eruptions and lava flows on Kilauea: but what's going on beneath Hawai'i's volcano?</a>
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<p>This means that any volatiles (dissolved gases such as water, carbon dioxide and sulphur dioxide) in the Kilauea magma are able to escape more easily compared to in a stickier, higher silica, magma that characterises subduction zone volcanoes.</p>
<p>And so “Hawaiian-style” eruptions are characterised by lava fountaining and flows of hot fluid lava that normally travel slow enough for people to walk away from and evacuate. This is exactly what we have been seeing over the last month in Kilauea’s East Rift Zone.</p>
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<p>In contrast, at subduction zone volcanoes – such as Fuego – the higher water content of the magma and the typically more silica-rich, sticky magmas erupt more explosively. It is harder for gas bubbles formed to escape as magma rises to the surface, which then take up more space and over pressure the system. </p>
<p>Subduction zone volcanoes can produce high columns of gas and ash reaching tens of kilometres into the atmosphere, and scalding hot, fast-moving, cloud-like currents of gas, ash and volcanic material. These pyroclastic flows, or “pyroclastic density currents”, race down the volcano at speeds over 80 km/hr. </p>
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<p>Some news reports of eruptions at Fuego have incorrectly termed these pyroclastic flows “rivers of lava”. They are very different to lava flows and much more hazardous. </p>
<p>Clear and accurate communication of volcanic eruptions is crucial if those near the volcano are to understand the real risks.</p>
<h2>3. Pyroclastic flows are deadly</h2>
<p>Pyroclastic flows are extremely hazardous and deadly. They were responsible for deaths in Pompeii and Herculaneum from the AD79 eruption of Vesuvius in Italy. </p>
<p>Even the famous volcanologists <a href="http://volcano.oregonstate.edu/who-were-maurice-and-katia-krafft-how-did-they-die">Katia and Maurice Kraft</a> underestimated the reach of a pyroclastic flow during an eruption at Unzen volcano on June 3, 1991, which killed them along with many others. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-do-most-volcanologists-die-from-getting-too-close-to-volcanoes-82496">Curious Kids: Do most volcanologists die from getting too close to volcanoes?</a>
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<p>Historic subduction zone volcanic eruptions producing devastating pyroclastic flows include: </p>
<ul>
<li>Vesuvius, Italy AD 79</li>
<li>Tambora, Indonesia (1815)</li>
<li>Krakatau (Krakatoa), Indonesia (1883)</li>
<li>Mt Pelée, Caribbean (1902)</li>
<li>Mt St Helens, USA (1980)</li>
<li>Mt Pinatubo, Philippines (1991)</li>
<li>Unzen, Japan (1991).</li>
</ul>
<p>At Fuego, the loose, fragmented volcanic material (known as tephra) lying on the slopes after eruptions may be remobilised by rain to form volcanic mudflows known as lahars. These pose a significant current and future risk for the people surrounding Fuego compared to those living in Hawaii. </p>
<p>Pyroclastic density currents were the <a href="https://www.sciencedirect.com/science/article/pii/S0377027305001563">main cause of death from volcanic activity</a> in the 20th Century, killing around 45,000 people, almost 50% of all volcanic deaths in that time period (total deaths from volcanic activity is estimated to be 91,724).</p>
<p>While eyes are diverted toward eruptions in Central America and the Pacific Ocean, <a href="http://www.thejakartapost.com/travel/2018/06/04/alert-statuses-for-19-volcanoes-raised.html">Indonesia has raised the alert level</a> on some of its volcanoes this week. It now has <a href="https://magma.vsi.esdm.go.id/">21 volcanoes</a> on alert levels 2-4 (yellow, orange and red) on a scale of 1-4. </p>
<p>Local authorities will be vital in managing and communicating the risks of these volcanoes, as well as around Fuego and Kilauea.</p><img src="https://counter.theconversation.com/content/97775/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Handley receives funding from the Australian Research Council. </span></em></p>Important points about volcanoes: location matters, explosiveness can be predicted to an extent, and fast-moving flows of volcanic materials (known as pyroclastic flows) are deadly.Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/977072018-06-04T15:48:42Z2018-06-04T15:48:42ZFuego volcano: the deadly pyroclastic flows that have killed dozens in Guatemala<p>Dozens of people have been killed, and with many more missing, after Volcán de Fuego (Fuego) in Guatemala erupted on June 3 2018. </p>
<p>In recent years, Fuego has regularly ejected small gas and ash eruptions, which hold little risk to surrounding populations. But Fuego also has a reputation for producing larger explosive eruptions. These larger eruptions have two main primary hazards – falling ash and bombs (collectively known as tephra), and pyroclastic flows. Of these two, pyroclastic flows are the big killers, and are responsible for the deaths from the latest eruption. So, just what are these flows and why are they such killers? And what can people do to avoid them?</p>
<p>Footage taken from a road bridge over a dry valley from on June 3 at Fuego shows what appears to be a soft and billowing ash cloud gently flowing down the volcano. It looks innocuous. Spectators and officials watch mesmerised, but then the cloud moves into the valley and heads directly towards the bridge. Unease spreads and soon alarms sound before people rush away just in time. Footage shows the ash cloud quickly pass under and then over the bridge. These spectators escaped death by seconds, as this benign-looking ash cloud is the notorious killer that is a pyroclastic flow.</p>
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<p>Pyroclastic flows (also known as pyroclastic density currents) contain a hellish combination of hot rock fragments (pyroclasts), superheated air, and volcanic gases. You can expect temperatures of 100-600°C and they can travel fast – very fast on steep slopes. Speeds generally range between 70-200mph, but they have been <a href="https://pubs.usgs.gov/gip/msh//pyroclastic.html">recorded reaching 450mph</a>. As they are heavier (denser) than air, they tend to be funnelled into valleys. But their higher density also gives them momentum, so they can travel up the sides of valleys, and even over mountains. The worst place to be when a pyroclastic flow is on the move is in a valley, which is why the spectators at the road bridge were lucky to escape. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221573/original/file-20180604-175451-17vzn9t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Small-medium pyroclastic flows at Mayon Volcano.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Pyroclastic_flows_at_Mayon_Volcano.jpg">C G Newhall</a></span>
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<p>What surprised many volcanologists (including us) is that people were actually standing and taking pictures while watching this billowing cloud descend. It is certainly a hypnotic and beautiful phenomenon to observe, but any volcanic cloud moving even vaguely in your direction is a clear sign to flee. This suggests that further education of people living in and around Fuego of its volcanic hazards would not only be helpful, it would save lives.</p>
<p>It is rare that eruptions from Fuego produce such large pyroclastic flows that travel so far. This leaves the authorities in an impossible situation. Because if you create exclusion zones based on worst-case scenarios, then decades if not centuries may pass without a worst-case eruption. And all that time people will be grumbling about good and fertile land being inaccessible without good reason.</p>
<h2>Other deadly incidents</h2>
<p>One notorious example of a pyroclastic flow happening elsewhere was the <a href="https://www.theguardian.com/world/2002/apr/28/physicalsciences.highereducation">eruption of Mount Pelée</a> on the island of Martinique on May 8 1902. Pyroclastic flows destroyed the town of Saint-Pierre and killed an estimated 30,000 people. Only a handful survived, one of whom was a prisoner in a jail cell. This was the largest loss of life from a pyroclastic flows in the past two centuries.</p>
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<img alt="" src="https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=843&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=843&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=843&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1060&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1060&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221574/original/file-20180604-175425-yogfod.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1060&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Pyroclastic flows from Mount Pelée killed 30,000 thousand people.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Pelee_1902_2.jpg">Angelo Heilprin</a></span>
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<p>One of the most famous historical examples of the devastation and loss of life caused by pyroclastic flows is what happened at Pompeii and Herculaneum when Vesuvius erupted in 79AD. An important lesson from this eruption is the fickleness of human memory. Because Vesuvius had been dormant for at least 700 years, it wasn’t recognised as a potential threat. </p>
<p>Volcanologists know from their studies that the frequency of large eruptions at a specific volcano may be one every few centuries or every few thousand years. But on a human time scale these numbers lose impact because there may be no aged relatives around who remember past eruptions, and so a complacent sense of “all is well” pervades. </p>
<p>Many communities living around volcanoes have other more immediate concerns, including other natural hazards. It’s an unresolved paradox. The eruption of Vesuvius produced a number of pyroclastic flows which led to the deaths of at least 1,400 people, and the burial of the settlements by volcanic material. <a href="https://www.bbc.co.uk/news/world-europe-44303247">Recent excavations</a> revealed evidence of a new type of death from this eruption – a person being struck by a large block, possibly carried by one of the pyroclastic flows. </p>
<p>It is too early to tell what will happen next with Fuego. But given its recent history, this eruption is an unusually large and extreme event. Fortunately, these tend to be infrequent. It is sincerely hoped that there will be no sudden repeat of the large and far-travelled pyroclastic flows that took so many lives. Whatever happens, there will be a huge amount of work to do in rebuilding communities and working through collective grief.</p><img src="https://counter.theconversation.com/content/97707/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca Williams has received funding from NERC. </span></em></p><p class="fine-print"><em><span>Dave McGarvie does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Pyroclastic flows are biggest danger in these eruptions.Dave McGarvie, School of Physical Sciences, The Open UniversityRebecca Williams, Lecturer in Volcanology, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/969192018-05-24T20:04:57Z2018-05-24T20:04:57ZEruptions and lava flows on Kilauea: but what’s going on beneath Hawai'i’s volcano?<p>Over the past few weeks we’ve seen increasingly <a href="https://weather.com/safety/news/2018-05-21-hawaii-kilauea-volcano-aerial-photos">spectacular images</a> reported in the news of the ongoing eruption at Kilauea volcano, on the Pacific island of Hawai'i.</p>
<p>These have been tempered by reports of <a href="http://www.news.com.au/world/north-america/hawaiis-kilauea-volcano-erupts-sending-ash-cloud-into-air-and-forming-gas-glass-as-lava-hits-sea/news-story/0cc553c50cfdfd56a3ba000c91309114">growing destruction</a>, with houses and infrastructure bulldozed, buried or burned by lava flows. </p>
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Read more:
<a href="https://theconversation.com/trouble-in-paradise-eruptions-from-kilauea-volcano-place-the-hawaiian-island-on-red-alert-96469">Trouble in paradise: eruptions from Kīlauea volcano place the Hawaiian island on red alert</a>
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<p>Yet Kilauea is one of the world’s most active volcanoes, and has been erupting continually since 1983. So what has triggered this sudden change in activity, threatening homes and livelihoods? The answer relates to what is happening beneath the volcano. </p>
<h2>Kilauea volcano</h2>
<p>Activity at Kilauea is driven by the buoyant upwelling of a plume of hot mantle, which provides the heat to generate magma beneath the volcano. This magma has the potential to erupt from several different locations, or vents, on the volcano.</p>
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<span class="caption">Click on the three blue markers to reveal more.</span>
<span class="attribution"><a class="source" href="https://www.google.com/maps/d/u/0/embed?mid=1_H52K2m3P5-1awLPjrHY1ySXN7IiXA6N">Google Maps/The Conversation</a></span>
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<p>Typically, the crater at the summit of the volcano is where eruptions are expected to occur, but the geology of Kilauea is complex and a rift on the eastern side of the volcano also allows magma to erupt from its flanks. </p>
<p>Over the past decade both the summit crater and a vent on the eastern rift, called Pu’u O’o, have been continually active. The summit crater has hosted a <a href="https://www.youtube.com/watch?v=y0lNb4Hz7ac">lava lake</a> since March 2008.</p>
<p>Lava lakes are relatively rare features seen at only a handful of volcanoes around the world. The fact that they do not cool and solidify tells us that lava lakes are regularly replenished by fresh magma from below.</p>
<p>In contrast, Pu’u O’o, 18km east of the summit crater, has been pouring out <a href="https://pubs.usgs.gov/fs/2012/3127/fs2012-3127.pdf">lava flows since 1983</a>. In the first 20 years of this eruption, 2.1km³ of lava flows were produced, equivalent in volume to 840,000 Olympic swimming pools. All of this tells us that Kilauea volcano regularly receives lots of magma to erupt. </p>
<h2>Current eruptions</h2>
<p>Over the <a href="http://volcano.si.edu/volcano.cfm?vn=332010&vtab=Weekly#May2018">past three weeks</a> activity at Pu’u O’o has stopped, while a series of fissures has opened roughly 20km further east in a subdivision known as Leilani Estates.</p>
<p>This area was previously affected by lava flows in <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/geo_hist_1955.html">1955</a>. </p>
<p>To date, 23 fissures have opened, starting off simply as cracks in the ground, with some developing into highly active vents from which significant lava flows are forming. </p>
<p>At the moment, the longest flows are about 6km long, having <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_chronology.html">reached the ocean</a>. This is a further <a href="https://theconversation.com/lava-in-hawaii-is-reaching-the-ocean-creating-new-land-but-also-corrosive-acid-mist-96947">cause for concern</a>, as the lava reacts with seawater to form a corrosive mist.</p>
<p>Meanwhile, at the summit of the volcano, the lava lake has drained from the crater, sparking <a href="https://theconversation.com/trouble-in-paradise-eruptions-from-kilauea-volcano-place-the-hawaiian-island-on-red-alert-96469">fears of more explosive eruptions</a>, as draining magma interacts with groundwater. </p>
<p>Satellite instruments and high-resolution GPS are being used to monitor changes in the shape of the volcano and have found that the <a href="https://www.facebook.com/USGSVolcanoes/photos/a.984262971602264.1073741827.984239038271324/2033888749973009/?type=3&theater">summit region is deflating</a>, while the lower east rift zone, where new fissures have opened in recent days, is inflating.</p>
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<p>The magma reservoirs that feed eruptions on Kilauea can be imagined as balloons, which grow when they are filled and shrink when they are emptied. Deflation at the summit, combined with observations that the lava lake has drained (at a rate of up to 100m over two days!), suggest that the magma reservoir feeding the summit is emptying.</p>
<p>Where is the magma going? Observations of ground inflation around the newly opened fissures to the east indicate that the magma is being diverted down the east rift and accumulating and erupting there instead.</p>
<p>Exactly what has caused this rerouting of the magma is still not clear. A <a href="https://earthquake.usgs.gov/earthquakes/eventpage/us1000dyad#executive">magnitude 6.9 earthquake</a> occurred in the area on May 4 and this may have opened a new pathway for magma to erupt, influencing the geometry of the lower east rift zone.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=580&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=580&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=580&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=729&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=729&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=729&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A Landsat8 image (top) of Kilauea volcano taken on March 15, 2018. The relative location of the various vents are marked, and a red, glowing lava flow can just be seen in the north-east of the image. The graphic (bottom) shows an inferred magma pathway below the volcano.</span>
<span class="attribution"><span class="source">NASA/Chris Firth</span>, <span class="license">Author provided</span></span>
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<h2>Lessons for the future</h2>
<p>By combining measurements from Kilauea of ground deformation, earthquake patterns and gas emissions during the current eruption, with observations of the lava that is erupted, volcanologists will be able to piece together a much clearer picture of what triggered this significant change in eruption over the past few weeks.</p>
<p>This knowledge will be crucial in planning for future eruptions, both at Kilauea and at other volcanoes. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/lava-in-hawaii-is-reaching-the-ocean-creating-new-land-but-also-corrosive-acid-mist-96947">Lava in Hawai'i is reaching the ocean, creating new land but also corrosive acid mist</a>
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<p>Eruptions from the flanks of a volcano can pose a much more significant hazard for the local population than those from a volcano’s summit, as many more people live in the areas that are directly affected.</p>
<p>This has been amply displayed over the past few weeks on Kilauea by the fissures opening in people’s gardens and lava flows destroying homes and infrastructure.</p>
<p>But Kilauea is not the only volcano to have flank eruptions. For example, lava flows famously emerged from the lower slopes of <a href="https://www.researchgate.net/publication/227129509">Mt Etna in 1669</a>, destroying villages and partially surrounding the regional centre of Catania, on the east coast of Sicily, Italy.</p>
<p>Lessons learned from the current eruption of Kilauea can equally be applied to other volcanoes, like Etna, where more densely populated surroundings mean that the hazards posed by such an eruption would be even greater.</p>
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<a href="https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=456&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=456&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=456&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=573&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=573&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220244/original/file-20180524-90281-15s9gae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=573&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Lava fountains form fissure 22 on the lower east rift zone of Kīlauea volcano, in Hawai'i.</span>
<span class="attribution"><a class="source" href="https://www.usgs.gov/media/images/k-lauea-volcano-lava-fountain-fissure-22">USGS</a></span>
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<p class="fine-print"><em><span>Chris Firth does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The current eruption of Kilauea on Hawai'is big island can tell us a lot about what is going on beneath the volcano and may provide lessons for future eruptions.Chris Firth, Lecturer in Geology, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/969472018-05-22T14:43:37Z2018-05-22T14:43:37ZLava in Hawai'i is reaching the ocean, creating new land but also corrosive acid mist<p>There is something special and awe-inspiring about watching new land form. This is what is now happening in Hawai’i as its <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/status.html">Kīlauea volcano erupts</a>. Lava is reaching the ocean and building land while producing spectacular plumes of steam. These eruptions are hugely important for the creation of new land. But they are also dangerous. Where the lava meets the ocean, corrosive acid mist is produced and glass particles are shattered and flung into the air. Volcanic explosions can also hurl lava blocks hundreds of metres and produce waves of scalding hot water. </p>
<p>At Kīlauea, lava is erupting from a line of vents on the volcano’s flanks, and is moving downslope to the edge of the island, where it enters the ocean. This is a process that has been witnessed many times at Hawai’i and other volcanic islands. And it is through many thousands of such eruptions that volcanic islands like Hawai’i form.</p>
<p>The new lava being added to Hawai’i by this latest Kīlauea eruption replaces older land that is being lost by erosion, and so prolongs the island’s lifespan. In contrast, older islands to the north-west have no active volcanoes, so they are being eroded by the ocean and will eventually disappear beneath the waves. The opposite is happening to the south-east of Hawai’i, where an underwater volcano (Lōʻihi Seamount) is building the foundations of what will eventually become the next volcanic island in this area.</p>
<h2>How lava gets to the ocean at Hawai’i</h2>
<p>The lava erupting from the current Kīlauea vents has a temperature of roughly 1150 degrees °C, and has a journey of between 4.5km and 5.5km to reach the ocean. As this lava moves swiftly in channels, it loses little heat and so it can enter the ocean at a temperature of over 1000 degrees°C.</p>
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<img alt="" src="https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">When lava meets the sea, new land is formed.</span>
<span class="attribution"><a class="source" href="http://www.epa.eu/disasters-photos/volcanic-eruption-photos/fissure-20-flow-reaches-the-ocean-photos-54352112">EPA</a></span>
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<h2>What happens when lava meets the ocean?</h2>
<p>We are witnessing one of the most spectacular sights in nature - billowing white plumes of steam (technically water droplets) as hot lava boils seawater. Although these billowing steam clouds appear harmless, they are dangerous because they contain small glass shards (fragmented lava) and acid mist (from seawater). This acid mist known as “laze” (lava haze) can be hot and corrosive. If anyone goes to near it, they can experience breathing difficulties and irritation of their eyes and skin.</p>
<p>Apart from the laze, the entry of lava into the ocean is usually a gentle process, and when steam is free to expand and move away, there are no violent steam-driven explosions.</p>
<p>But a hidden danger lurks beneath the ocean. The lava entering the sea breaks up into blobs (known as pillows), angular blocks, and smaller fragments of glass that form a steep slope beneath the water. This is called a lava delta. </p>
<p>A newly formed lava delta is an unstable beast, and it can collapse without warning. This can trap water within the hot rock, leading to violent steam-driven explosions that can hurl metre-sized blocks up to 250 metres. Explosions occur because when the water turns to steam it suddenly expands to around 1,700 times its original volume. <a href="https://volcanoes.usgs.gov/observatories/hvo/hawaii_ocean_entry.html">Waves of scalding water</a> can also injure people who are too close. People have died and been seriously injured during lava delta collapses </p>
<p>So, the ocean entry points where lava and seawater meet are doubly dangerous, and anyone in the area should pay careful attention to official advice on staying away from them.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Pillow Lavas form underneath the ocean.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Nur05028_-_pile_of_pillow_lava.jpg">National Oceanic & Atmospheric Adminstration (NOAA)</a></span>
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<h2>What more can we learn from these eruptions?</h2>
<p>Once lava deltas have cooled and become stable they represent new land. <a href="http://sp.lyellcollection.org/content/202/1/91">Studies</a> have revealed that lava deltas have distinctive features, and this has enabled volcanologists to recognise lava deltas in older rocks.</p>
<p>Remarkable examples of lava deltas have been discovered near the top of extinct volcanoes (called tuyas) in Iceland and Antarctica. These deltas can only form in water and the only plausible source of this water in this case is melted ice. This means that these volcanoes had melted water-filled holes up to 1.5km deep in ice sheets, which is an astonishing feat. In fact, these lava deltas are the only remaining evidence of long-vanished ice sheets. </p>
<p>It is a privilege to see these incredible scenes of lava meeting the ocean. The ongoing eruptions form part of the natural process that enables beautiful volcano islands like Hawai'i to exist. But the creation of new land here can also bring danger to those who get too close, whether it be collapsing lava deltas or acid mist.</p><img src="https://counter.theconversation.com/content/96947/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:ian.skilling@southwales.ac.uk">ian.skilling@southwales.ac.uk</a> received funding from National Science Foundation in US. </span></em></p><p class="fine-print"><em><span>Dave McGarvie does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>At Kīlauea in Hawai'i, a recent volcanic eruption has created some of the most spectacular sights in nature. But also danger for those around it.Dave McGarvie, School of Physical Sciences, The Open UniversityIan Skilling, Senior Lecturer (Volcanology), University of South WalesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/949772018-04-16T20:52:01Z2018-04-16T20:52:01ZHow the Pilbara was formed more than 3 billion years ago<figure><img src="https://images.theconversation.com/files/214906/original/file-20180416-584-12wql9z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In the field studying the rock association in the Doolena Gap greenstone belt, 30 km north of Marble bar in the Pilbara region of Western Australia.</span> <span class="attribution"><span class="source">David Murphy</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The remote Pilbara region of northern Western Australia is one of Earth’s oldest blocks of continental crust, and we now think we know how it formed, as explained in research <a href="http://nature.com/articles/doi:10.1038/s41561-018-0105-9">published today in Nature Geoscience</a>.</p>
<p>The region is well known for its rich, ancient Aboriginal history extending over at least 40,000 years. It also features an incredibly diverse ecosystem, with many species found nowhere else.</p>
<p>The architecture of this ancient crust leads to a distinctive landscape as viewed from above, with light-coloured oval features that are granite domes surrounded by dark belts of volcanic and sedimentary rocks, known as greenstone belts.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/target-earth-how-asteroids-made-an-impact-on-australia-92836">Target Earth: how asteroids made an impact on Australia</a>
</strong>
</em>
</p>
<hr>
<p>This unique geological architecture bears witness to the history of our planet.</p>
<iframe src="https://www.google.com/maps/embed?pb=!1m14!1m12!1m3!1d1121615.4829093271!2d118.5212715870071!3d-21.183171415849873!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!5e1!3m2!1sen!2sau!4v1523850308436" width="100%" height="600" frameborder="0" style="border:0" allowfullscreen=""></iframe>
<h2>Billions of years ago</h2>
<p>The Pilbara region began to form more than 3.6 billion years ago and our research supports the idea that its rocks were not formed through the plate tectonics processes that we see in operation today.</p>
<p>In plate tectonics, the outermost layer of Earth consists of fragmented, stiff “tectonic plates” that drift across the planetary surface, interacting at their boundaries. New crust is generated and destroyed at plate boundaries and this process is associated with most of Earth’s current volcanic and earthquake activity. </p>
<p>The plate boundaries are generally composed of fairly straight segments, hundreds of kilometres long. Witness the long chain of volcanoes along South America’s west coast.</p>
<p>So why do the rocks in the Pilbara exhibit this unusual granite-greenstone geometry? </p>
<p>In our <a href="http://nature.com/articles/doi:10.1038/s41561-018-0105-9">research</a> we detail how these rocks formed, describing a series of “gravitational overturn” events that affected the ancient crust in the East Pilbara well before plate-tectonic processes began around 3.2 billion years ago.</p>
<h2>Gravitational overturn</h2>
<p>What is a gravitational overturn? The young Earth was roasting hot. Its large heat content resulted in widespread volcanism. It was too warm for the rigid plates required for plate tectonics to operate.</p>
<p>Imagine retrieving a long-forgotten chocolate bar from your pocket, which then bends and drips over your fingers as you attempt to enjoy a snack. (Modern plates resemble a cold chocolate bar straight from the fridge: it does not bend and breaks when you want a corner.) </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214934/original/file-20180416-105522-1y0m2u9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Photograph of at least 3.5 billion year old banded-iron formation showing intensive deformation as a result of gravitational overturn until 3.41 billion years ago.</span>
<span class="attribution"><span class="source">Daniel Wiemer</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The hot early Earth erupted thick piles of basalt lavas that formed a dense crust barely supported by the underlying mantle. The base of this cooling crust experienced further heating from the hot mantle below until it started to melt, generating relatively buoyant granitic magmas.</p>
<p>This process led to an unstable stratification of the ancient proto-crust: low-density granites were overlain by high-density basalts. Due to the high heat, both layers could bend and flow, leading to instability.</p>
<p>The granitic blobs wanted to rise and the basalts wanted to sink. Scientists call the rising blobs “plumes” and the reorganisation process “gravitational overturn”.</p>
<p>In the early Earth, with its high temperatures and soft crust, the granites rose up through the crust where it formed buoyant stable crust, while most of the dense basalt crust sunk into the mantle. This process is preserved in the Pilbara as the oval-shaped granite domes and the preserved remnants of the basalt crust as the greenstone belts.</p>
<h2>The landscape today</h2>
<p>North of Marble Bar, by looking at rock fabrics, we discovered the remains of the oldest recorded gravitational overturn in the Pilbara. Intensely deformed rocks preserve traces of the ascent of a rising granite plume and the associated down-going of the dense volcanic crust. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214931/original/file-20180416-127631-3lm0hq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A rugged landscape formed above the deformed greenstone belts in the Doolena Gap greenstone belt, 30km north of Marble bar.</span>
<span class="attribution"><span class="source">David Murphy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our field observations, geochemical analyses and thermodynamic models demonstrate that rocks collected from the dome margin represent high silica magma that originally melted at a depth of around 42km before crystallising as granites at 20km.</p>
<p>Uranium-lead dating of zircon in the laboratory revealed that these rocks crystallised from 3.6-billion to 3.5 billion years ago.</p>
<p>The intensely sheared rocks at the boundary of the rising dome and sinking volcanic rocks contain a metamorphic mineral, titanite, that formed during the gravitational overturn.</p>
<p>We dated several of these mineral grains and they average 3.42 billion years old.</p>
<p>By dating both pre- and post-gravitational overturn rock associations, we were able to constrain its duration to a 40 million year period.</p>
<p>Combining our research with the published work of <a href="https://doi.org/10.1016/j.epsl.2014.04.025">other</a> <a href="http://sp.lyellcollection.org/content/389/1/1">geologists</a>, it appears that the Pilbara experienced at least three gravitational overturns separated by 100-million-year intervals.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=482&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=482&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=482&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=606&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=606&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214938/original/file-20180416-584-1tqbl0k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=606&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Back scatter electron image of titanite taken at Central Analytical Research Facility, QUT. The upper two images are primary magmatic images that have undergone deformation and alteration during the gravitational overturn. The lower two images are metamorphic titanite that formed during the gravitational overturn. The rectangular shapes in the bottom right image are laser pit from the dating process.</span>
<span class="attribution"><span class="source"> Lana Wenham</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>After the final overturn 3.2 billion years ago, the Pilbara crustal block was finally sufficiently robust and buoyant to survive plate tectonics lasting even until today.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-active-volcanoes-on-my-asia-pacific-ring-of-fire-watch-list-right-now-90618">Five active volcanoes on my Asia Pacific 'Ring of Fire' watch-list right now</a>
</strong>
</em>
</p>
<hr>
<p>We speculate that the cyclicity of overturn events in the Pilbara is the ancient equivalent of the 500- to 600-million-year <a href="http://www.dictionary.com/browse/wilson-cycle">Wilson cycle</a>, one full round of crust from formation until destruction in the plate tectonic style in existence since 3.2 billion years ago.</p>
<p>The Pilbara keeps inspiring scientists worldwide to finding answers to one of humankind’s great questions: how did nature provide the platform for the eventual evolution of life? </p>
<p>We plan to test the idea of characteristic ancient overturn cycles elsewhere in the Pilbara and on other continents where ancient crust is preserved.</p><img src="https://counter.theconversation.com/content/94977/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charlotte Allen works for QUT</span></em></p><p class="fine-print"><em><span>Christoph Schrank receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Daniel Wiemer and David Murphy do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The remote Pilbara region of Western Australian formed many billions of years ago when the Earth was much hotter and the crust softer than it is today.David Murphy, Lecturer in Geoscience, Queensland University of TechnologyCharlotte Allen, Senior Research Officer (Elements & Isotopes), Queensland University of TechnologyChristoph Schrank, Senior Lecturer, Queensland University of TechnologyDaniel Wiemer, Researcher, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/910532018-02-07T19:00:46Z2018-02-07T19:00:46ZMore bad news for dinosaurs: Chicxulub meteorite impact triggered global volcanic eruptions on the ocean floor<figure><img src="https://images.theconversation.com/files/205347/original/file-20180207-74479-1ragczb.jpg?ixlib=rb-1.1.0&rect=229%2C0%2C4290%2C3149&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Seismic shockwaves after a meteorite’s collision could affect systems all over the planet.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/large-meteor-burning-glowing-hits-earths-488993764">solarseven/Shutterstock.com</a></span></figcaption></figure><p>The end of the Cretaceous period 66 million years ago was a rough time to be living on Earth.</p>
<p>Three global catastrophes occurred nearly simultaneously: The <a href="https://doi.org/10.1126/science.208.4448.1095">Chicxulub meteorite slammed</a> into what is now Mexico’s Yucatan Peninsula, the massive <a href="https://doi.org/10.1038/333843a0">Deccan Traps volcanic province in modern-day India erupted</a>, and some three-quarters of Earth’s plants and animals, including all non-avian dinosaurs, went extinct. The occurrence of these three events at the same time in our planet’s history has fueled a decades-long <a href="https://doi.org/10.1016/S1631-0713(03)00006-3">debate about causal links</a>. Either a large sequence of volcanic eruptions or an extraterrestrial impact could conceivably cause a mass extinction – but were they all somehow connected?</p>
<p>As Earth scientists, we have reason to believe that there may be another event to add to the list. <a href="http://advances.sciencemag.org/content/4/2/eaao2994">Our new research</a>, published in Science Advances, shows that the Chicxulub impact may have triggered additional volcanic activity far from the Deccan Traps – along tens of thousands of miles of undersea volcanic ridges that lie at the edges of tectonic plates. The meteorite impact caused large seismic waves that traveled around the globe and were apparently capable of flushing magma out of the mantle and into the oceanic crust. This would presumably be more bad news for the dinosaurs and other flora and fauna of the time.</p>
<h2>Ripple effects of seismic activity</h2>
<p>It is well known that seismic activity can trigger a variety of hydrologic phenomena, and sometimes even volcanic eruptions. In the aftermath of nearby large earthquakes, <a href="https://doi.org/10.1038/ncomms8597">dry streams can start flowing</a>, well levels can go up or down, and <a href="https://doi.org/10.1146/annurev.earth.34.031405.125125">geysers sometimes erupt</a>. Seismicity also sets off volcanic activity, but only when conditions are just right – it’s only about <a href="https://doi.org/10.1146/annurev.earth.34.031405.125125">0.4 percent of explosive volcanic eruptions</a> that might be triggered by large earthquakes.</p>
<p>So could the massive earthquake generated when the Chicxulub meteorite crashed into Earth be related to the ongoing eruptions in the Deccan Traps? This volcanic province covered much of India with lava flows in less than a million years. A University of California, Berkeley-led team of researchers (including one of us, Leif Karlstrom) <a href="https://doi.org/10.1130/B31167.1">revisited the possibility of a connection</a> between these two events.</p>
<p>The most recent efforts to date these eruptions have clearly shown that the <a href="https://doi.org/10.1126/science.aaa0118">Deccan Traps began spewing lava</a> before the meteorite impact and the mass extinction occurred. But the Berkeley-led study suggested that the <a href="https://doi.org/10.1126/science.aac7549">Chicxulub impact triggered a rapid increase in their eruption rate</a>. If true, all three events could conceivably be connected: The impact would be followed by accelerated volcanic activity that could contribute to the mass extinction.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205141/original/file-20180206-88775-1vu003i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Underwater lava flows ooze out between tectonic plates, as at Axial Seamount, where it lies on top of older lavas.</span>
<span class="attribution"><span class="source">Bill Chadwick, Oregon State University, and ROV Jason, Woods Hole Oceanographic Institution</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Looking to the ocean floor</h2>
<p>If the triggering-by-impact hypothesis is right, we’d expect that other volcanic systems would have been set off as well.</p>
<p>At any given time, the vast majority of the volcanic activity on Earth isn’t occurring in continent-covering floods of magma or in explosions like at Mount St. Helens. It’s on the seafloor, where the tectonic plates are spreading apart. As the Earth’s crust splits, the mostly solid mantle layer rises to fill the space created. It melts as it decompresses on the way up.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=203&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=203&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=203&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=255&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=255&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205132/original/file-20180206-88799-1rj8m9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=255&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Illustration of a mid-ocean ridge, with magma rising from the mantle and erupting through the crust at the boundary between tectonic plates.</span>
<span class="attribution"><span class="source">Background, E. Paul Oberlander, WHOI Graphic Services. Inset, Bill Chadwick, Oregon State University, and ROV Jason, Woods Hole Oceanographic Institution. Modified by Joseph Byrnes</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This new magma percolates its way to the surface and fuels nearly continuous volcanic activity along what are known as <a href="https://en.wikipedia.org/wiki/Mid-ocean_ridge">mid-ocean ridges</a>. This process creates practically all of the crust on the bottom of the ocean. Since the <a href="http://www.earthbyte.org/Resources/agegrid2008.html">ages of the seafloor are relatively well-known</a>, it preserves a record of oceanic volcanic activity stretching back over 100 million years. This remarkable record of volcanic activity creates an opportunity to test the triggering hypothesis.</p>
<p><a href="http://advances.sciencemag.org/content/4/2/eaao2994">In our new study</a>, we used publicly available data sets to make a record of the structure of the seafloor stretching back 100 million years. Since better topographic maps exist for <a href="https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA02820">Mars</a> and <a href="https://sos.noaa.gov/datasets/venus-topography/">Venus</a> than do for the <a href="http://topex.ucsd.edu/marine_topo/">Earth’s seafloor on a global scale</a>, we were forced to use indirect methods to look for variations in seafloor structures.</p>
<p>Minute variations in the strength of gravity at different locations as measured by satellites <a href="http://topex.ucsd.edu/marine_grav/mar_grav.html">provide the requisite mapping tool</a>. Spots that have an excess amount of rock sitting on the seafloor, as you’d expect to result from accelerated volcanic activity, will have a slightly stronger measurement for Earth’s gravitational field.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=298&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=298&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=298&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=375&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=375&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205133/original/file-20180206-88775-1s17005.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=375&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The time with the most small structural anomalies on the sea floor – indicating 8 percent more mass anomalies than on average – occurs at 66 million years ago and coincides with the age of the Chicxulub meteorite impact.</span>
<span class="attribution"><span class="source">Byrnes and Karlstrom, Sci. Adv. 2018;4: eaao2994</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>We then inspected the record of these “gravity anomalies” to look for any changes to the structure of the seafloor that happened quickly. We found an unusual abundance of these small structural anomalies on the seafloor happened within 1 million years of the Chicxulub impact. The gravity anomalies are consistent with roughly 650 foot high piles of excess material lying on 66-million-year-old seafloor in the Indian and Pacific Oceans.</p>
<p>The total volume of excess material is difficult to pin down, because a large amount of magma could have been injected into the lower crust where it would have a weaker gravitational signature. But we estimate that around the time of the Chicxulub impact, on the order of 23,000 to 230,000 cubic miles of magma erupted out of the mid-ocean ridges, all over the globe. This is on par with the largest eruptive events in Earth’s 4.5-billion-year history, including the Deccan Traps.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=261&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=261&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=261&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=327&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=327&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205136/original/file-20180206-88775-1h6n02.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=327&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dots mark areas on the seafloor that show high rates of spreading at the time of the Chicxulub impact 66 million years ago. Colors indicate the maximum gravity anomaly within 2 degrees.</span>
<span class="attribution"><span class="source">Byrnes and Karlstrom, Sci. Adv. 2018;4: eaao2994</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Refining the picture</h2>
<p>Our observations suggest the following sequence of events at the end of the Cretaceous period. Just over 66 million years ago, the Deccan Traps start erupting – likely initiated by a plume of hot rock rising from the Earth’s core, similar in some ways to what’s happening beneath Hawaii or Yellowstone today, that impinged on the side of India’s tectonic plate. The mid-ocean ridges and dinosaurs continue their normal activity.</p>
<p>About 250,000 years later, Chicxulub hits off the coast of what will become Mexico. The impact causes a massive disruption to the Earth’s climate, injecting particles into the atmosphere that will eventually settle into <a href="https://doi.org/10.1126/science.1177265">a layer of clay found across the planet</a>. In the aftermath of impact, volcanic activity accelerates for perhaps tens to hundreds of thousands of years. The mid-ocean ridges erupt large volumes of magma, while the Deccan Traps eruptions flood lava across much of the Indian subcontinent. In the end, three-quarters of the Earth’s plant and animal species have disappeared; the only remaining dinosaurs are the feathered, flying variety, normally referred to as birds. </p>
<p>Now, the goal is to further refine our understanding of each event and their interactions. Was there enough mid-ocean ridge activity to contribute to the mass extinction, or was the triggered submarine volcanism merely a symptom of some more significant planetary ailment? Were other volcanic systems triggered by the Chicxulub impact? Which played a larger role in driving the extinction: the volcanism or the meteor?</p>
<p>What is clear is that this new research points to global-scale connections between catastrophes, a good reminder that events happening on the other side of the planet can have effects felt everywhere.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/8wy33t0U1DE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Massive eruption of magma may have contributed to mass extinction at the end of the Cretaceous.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/91053/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Leif Karlstrom receives funding from the National Science Foundation.</span></em></p><p class="fine-print"><em><span>Joseph Byrnes does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research suggests a new threat to life on Earth from the meteorite’s crash: Via seismic waves, the impact triggered massive undersea eruptions, as big as any ever seen in our planet’s history.Leif Karlstrom, Assistant Professor of Earth Sciences, University of OregonJoseph Byrnes, Postdoctoral Associate of Earth Sciences, University of MinnesotaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/824962017-11-14T19:13:44Z2017-11-14T19:13:44ZCurious Kids: Do most volcanologists die from getting too close to volcanoes?<figure><img src="https://images.theconversation.com/files/182040/original/file-20170815-32006-nzw0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Volcanologists often visit active volcanoes in order to observe eruptions and collect samples of lava and ash.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/monusco/13845573423/in/photolist-aq16Ln-5z5QEG-aeSgN1-7SNEQ-6PCKD5-7VGbsu-n6u1ga-n6vQaq-n6tP6M-n6tY1v-n6vSAC-n6tRfr-n6ubBa-iutm6t-qu4YpS-7VPwZH-fmhyQA-5KoDkh-oCjX1c-7Y8DJP-vAkbf-vAjXR-7Ucr8K-q7aKQk-bnKXb5-bAGLMV-4WvhpC-bkM4x6">Flickr/MONUSCO Photos</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!</em> </p>
<hr>
<blockquote>
<p><strong>Do most volcanologists die because of studying volcanoes at close range? – Tobias, age 5, Malmsbury.</strong> </p>
</blockquote>
<p>Volcanoes show us a glimpse of what is deep in the Earth below. They also show us how powerful nature can be. Studying volcanoes is exciting, but can also be dangerous.</p>
<p>According to my calculations – based on a range of media reports and books – 31 volcanologists have died over the past 60 years while they were studying volcanoes.</p>
<p>These have been tragic events for their families and their co-workers. The period with the most volcano-scientists killed was between 1991 and 1993: 12 people died in four separate eruptions. </p>
<p>Two of these eruptions have become the most famous: one in 1991 at Mount Unzen, Japan, and one in 1993 at Galeras, Colombia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182041/original/file-20170815-32006-zisf01.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lava can reach temperatures as high as 1200˚C.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/ztjackson/3241111818/in/photolist-5WpxCf-aPSwi2-aPUaTK-ptEoev-e3bk2i-aPT15Z-fnaT1-e1dqcm-5rNzWh-5Ynn8F-RJaicK-64foU6-b2x3qv-EpTsV-oR2jFe-U3RfhA-HYEMo-9rhHXY-9uGbh2-JiJGSz-dYMAvK-UJTppq-qoSXNi-q3DExU-9WDg-dWh6YB-4AxrTX-LMfoG-9rhNKA-6kkdhk-9rhNnC-4pZCNS-w7eCV-aCMBP2-y4rFv-bsi6RJ-g9gBrM-2G5vHz-4KRaa-dsSuC-2TXgZf-SnRLqx-89j9V9-vgyL1-5YspQb-LMpyk-5Yo9Dn-5G7mF5-9iXz3E-SY4Ky1">Flickr/Zach Jackson</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-do-sharks-sneeze-77399">Curious Kids: Do sharks sneeze?</a>
</strong>
</em>
</p>
<hr>
<p>At the Mount Unzen eruption, a sticky lava dome made up of hot fluid rock with crystals and gases built up on its top. When the dome grows really tall, it becomes unstable and collapses. This causes a big flow of pieces of the domes mixed with hot gases travelling really fast down the mountain. This is called a pyroclastic flow. </p>
<p>Two famous volcanologists who made awesome videos about erupting volcanoes, <a href="http://volcano.oregonstate.edu/who-were-maurice-and-katia-krafft-how-did-they-die">Maurice and Katia Krafft</a>, were caught and killed by such a pyroclastic flow at Mount Unzen.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/c5CAyaRIW8s?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The eruption at Galeras was one of the most powerful it had experienced in five years. However, no one saw it coming. At the time, 70 volcanologists were on the mountain studying it as part of a United Nations volcano hazard conference.</p>
<p>Sadly, it erupted with a big explosion when two scientists were in the crater and they died. Four others were killed by ballistic blocks, called bombs, that hit them like cannon balls. One survivor, Dr. Stanley Williams, who was also badly hit during the explosion, wrote a <a href="https://www.goodreads.com/book/show/1132925.Surviving_Galeras">book</a> about it.</p>
<hr>
<p><strong><em>Read more: <a href="https://theconversation.com/curious-kids-how-do-satellites-get-back-to-earth-82447_">Curious Kids: How do satellites get back to Earth?</a></em></strong></p>
<hr>
<p>But do <em>most</em> volcanologists die because of studying volcanoes at close range? No. </p>
<p>There are more than 2000 people around the world studying volcanoes and most of them have to get close to a volcano from time to time, but only 31 have been killed on the job in 60 years. </p>
<p>It is not safe to go up any volcano, but as long as you respect the volcano and keep an eye on any signs of activity, you could still live another day.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182044/original/file-20170815-5720-mofaqt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scientists estimate that there are around 1500 active volcanoes around the world today. Every week 12 of them erupt.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/41812768@N07/15145861552/in/photolist-p5ouY1-jGU39-dn9NdU-U1poau-kbLscV-6baYUz-Ti3nAd-eKeHuT-q1JVY6-m5HQvf-b33DWk-NNTPoc-dn9KJt-kbLZeH-krd9pK-FPCNpk-4j9JR4-6ye4Tf-X5xoZU-p5aUzr-6v9tGK-qbzgoo-pJwgyN-r32jNT-oMVXL7-7SveVM-dPbqY5-5mi5G-r9VGEf-p5aVp2-XmjftP-oMVGCv-6yrdq2-dQZFX2-krfeAb-pJztm1-b33DGg-CPL9Cd-iKMN2v-pJu3sc-X6WiPz-i1fiS2-pJxv5T-dgCMEu-8hZoeX-i5AZCk-8xnvWR-jQtex-b9xv1P-p3oz65">Flickr/peterhartree</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:</em></p>
<p><em>* Email your question to curiouskids@theconversation.edu.au
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<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/82496/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jozua van Otterloo is a member of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). </span></em></p>Volcanologists study the formation and eruptions of volcanoes - surely one of the most interesting jobs around. However, it can also be very dangerous.Jozua van Otterloo, Assistant Lecturer in Volcanology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/783632017-05-30T12:32:56Z2017-05-30T12:32:56ZVenus has very few volcanoes – weirdly, this might be why it’s as hot as hell<figure><img src="https://images.theconversation.com/files/171352/original/file-20170529-25201-1hlmaaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-renderingvenus-resolution-best-quality-solar-580798888?src=cvbKNLlwMuWNBXqY1Qi-cg-3-90">MAX3D</a></span></figcaption></figure><p>In the quest to discover habitable planets, scientists look for qualities similar to those of Earth. We do this because Earth sustains life, of course, but it falls down when you consider Venus. Based on size, chemistry and position in the solar system, our neighbouring planet is the most Earth-like ever observed. Yet while Earth is the definition of habitable, the planet Venus is a barren, hot, hellish wasteland. </p>
<p>Geologists like myself are trying to understand why two almost identical planets became so different. This is one way we can assist the astrophysics community in the exciting hunt for habitable exoplanets. A key part of the puzzle is understanding the interplay between plate tectonics and volcanoes, since <a href="https://theconversation.com/how-the-air-we-breathe-was-created-by-earths-tectonic-plates-33278">this governs</a> the <a href="https://www.nature.com/ngeo/journal/v10/n5/full/ngeo2939.html">chemistry</a> of the air that supports life. </p>
<p>I have been part of a research collaboration to look at Venus’ volcanic history, the results of which have <a href="http://www.sciencedirect.com/science/article/pii/S0031920116301418">just been published</a> in the journal Physics of the Earth and Planetary Interiors. This study sheds some valuable light on the volcanic history of Earth’s sibling, and indirectly speaks towards how Venus became so hot in the first place. </p>
<p>The starting point to understanding Venus is the climate. The average surface temperature is 460°C – far too hot for liquid water and above the <a href="http://www.bbc.co.uk/earth/story/20160209-this-is-how-to-survive-if-you-spend-your-life-in-boilin-water">known thermal limit</a> for life, which is roughly 122°C. </p>
<p>This extreme heat is not simply because Venus is closer to the Sun, but also because it is enveloped by an über-greenhouse atmosphere. At 92 times the pressure of that on Earth, it’s enough to crush modern submarines. If you were standing on the Venusian surface it would be like swimming 1,000 metres below sea level – if the oceans were 460°C, that is. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/171350/original/file-20170529-25203-te8f7z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It ain’t half hot, mum.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/smile-crazy-scuba-diver-underwater-selfie-517820569?src=_2NAPKyoHbIWerQe60NRbw-1-85">Andrea Izzotti</a></span>
</figcaption>
</figure>
<p>The scorching temperature of Venus’s surface has many knock-on effects. It means, for example, that there’s no Earth-like plate tectonics. Most of the crust is too soft to snap, and it “<a href="https://www.nature.com/nature/journal/v508/n7497/full/nature13072.html">heals</a>” when broken. There have recently been suggestions that the planet might either have its <a href="http://www.nature.com/ngeo/journal/v10/n5/full/ngeo2928.html">own alternative version</a> of plate tectonics, <a href="http://www.sciencedirect.com/science/article/pii/S0032063315000409">or that</a> the high surface temperature results in the Venusian crust being physically decoupled from mantle flow beneath. At any rate, where plate tectonics <a href="http://www.sciencedirect.com/science/article/pii/B9780123964533000010">is behind</a> 90% of volcanic eruptions on Earth, this is not the case on Venus. </p>
<p>Venus does have volcanoes, but they’re all of the variety we call <a href="https://www.britannica.com/science/intraplate-volcanism">intra-plate or hotspots</a>, where plumes of magma rise up from the mantle and push their way to the surface via cracks in the crust. To study them, we compared them to the ones on Earth. We only considered volcanoes situated on Earth’s oceanic crust, since it is more comparable to the Venusian crust. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=516&fit=crop&dpr=1 754w, https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=516&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/171355/original/file-20170529-25203-i4zq4o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=516&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Kilauea in Hawaii, one of Earth’s hotspot volcanoes.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Kīlauea#/media/File:Puu_Oo_cropped.jpg">Wikimedia</a></span>
</figcaption>
</figure>
<p>The oceanic crust covers 60% of Earth’s surface. It is host to more than 100,000 hotspot volcanoes that have formed in less than 100m years. Conversely, Venus’ entire surface has produced only 70,000 individual volcanoes over a period of some 700m years (give or take 300m) – roughly the age of its outer crust. In other words, the difference in the rate of intra-plate volcano production is roughly ten times. (And bear in mind this is a comparison against only a small minority of the total number of volcanoes on Earth since it was formed.) </p>
<h2>Time travelling with argon</h2>
<p>To investigate whether Venus was always so volcanically challenged over its approximately 4.6 billion-year history, we called on the services of argon (Ar). This noble gas comes in three “flavours”, each with a slightly different mass (36, 38 and 40). We know that when Venus and Earth formed, 99% of their argon-36 and argon-38 quickly ended up in the air. </p>
<p>On the other hand, the argon-40 was only able to emerge slowly from the decay of an isotope of potassium that is stored in rocks. To find its way into the air, it then needed a mechanism to transport it there – the most efficient being volcanism. Because Earth’s atmosphere nowadays contains significantly more argon-40 than Venus’s, we can therefore assume Venus has been less volcanically active for its entire existence. </p>
<p>This conclusion probably sounds counter-intuitive – you might expect a hotter planet to be more volcanically active, not less so. When we studied this using rock deformation data, we found a similar phenomenon to the one that prevents plate tectonics on Venus. Because the crust is more like Play-Doh than the toffee brittle of Earth’s crust, it is difficult for magma to move through cracks and form volcanoes. On Venus, we predict, that most magma gets stuck in the Play-Doh – as you can see from the diagram below. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=282&fit=crop&dpr=1 600w, https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=282&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=282&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=355&fit=crop&dpr=1 754w, https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=355&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/171347/original/file-20170529-25236-1yqojwt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=355&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption"></span>
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<p>Incidentally, this lack of argon-40 in Venus’ atmosphere also probably explains why the planet has never had oceans. This is because the decaying potassium-40 that produces argon-40 exists within silicate minerals. Importantly, the crystal structure of silicate minerals also contains hydroxide anions, which is essentially water. </p>
<p>Indeed, the silicate mantles of both planets <a href="https://deepcarbon.net/feature/water-earth%E2%80%99s-transition-zone-directly-measured#.WSxiwTOZPeQ">can store</a> more than six times the mass of water present in Earth’s oceans. In other words, Earth’s volcanoes not only pumped out life-giving air, but also our oceans. </p>
<p>Furthermore, the great difference in the number of volcanoes may explain the runaway greenhouse effect on Venus. This is because fresh basalt exposed by volcanic eruptions can react with liquid water through a series of chemical reactions known as <a href="http://science.sciencemag.org/content/344/6182/373">carbonation</a> to remove carbon dioxide from the atmosphere. It is an excess of carbon dioxide that is responsible for the greenhouse effect. In short, it is no exaggeration to suggest that volcanoes may explain most of the fundamental differences between Earth and Venus. </p>
<p>For those of us at the <a href="https://www.st-andrews.ac.uk/exoplanets/index.html">St Andrews Centre for Exoplanet Science</a>, we’ll now return to the big picture. We aim to shed more light on how planets become habitable, and how to spot an Earth from a Venus at a distance so great it’s measured in light years. It’s certainly difficult doing this from Earth, but with a great set of PhD students, postdoctoral fellows and an open mind, I am confident we will get to the bottom of it.</p><img src="https://counter.theconversation.com/content/78363/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sami Mikhail receives funding from the Natural Environment Research Council (NE/P012167/1).</span></em></p>The planet is more similar to Earth than any other – except when it comes to supporting life.Sami Mikhail, Lecturer in Earth Sciences and Environmental Sciences & the Center for Exoplanet Science, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/677252016-10-27T14:06:20Z2016-10-27T14:06:20ZMagma power: how superheated molten rock could provide renewable energy<figure><img src="https://images.theconversation.com/files/143298/original/image-20161026-11265-1b7ixuo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Magma is molten rock below the Earth's surface. Once erupted, it becomes lava (pictured).</span> <span class="attribution"><span class="source">Benjamin van der Spek / shutterstock</span></span></figcaption></figure><p>Iceland is about to tap into water as hot as lava. Several kilometres below ground, a drilling rig named Thor will <a href="https://www.newscientist.com/article/2109872-iceland-drills-hottest-hole-to-tap-into-energy-of-molten-magma/">soon penetrate</a> the area around a magma chamber, where molten rock from the inner Earth heats up water that has seeped through the seafloor. This water – up to 1,000°C and saturated with corrosive chemicals – will eventually be piped up to the surface and its heat turned into usable energy.</p>
<p>It is a huge engineering challenge, and one which may usher in a new age of geothermal power production. Existing geothermal projects around the world need waters heated to less than 300°C, so why go to this extra effort and expense?</p>
<p>The answer is simple: water at the most extreme temperatures exists in a state described as “<a href="http://www.nottingham.ac.uk/supercritical/scintro.html">supercritical</a>”, where it behaves as neither a true liquid, nor a true gas, and is capable of retaining a phenomenal amount of energy. Supercritical water can generate up to <a href="http://sciencenordic.com/drilling-worlds-hottest-geothermal-well">ten times more power</a> than conventional geothermal sources.</p>
<p>Iceland is a nation built on about 130 volcanoes resting above a <a href="http://oceanexplorer.noaa.gov/facts/plate-boundaries.html">divergent plate boundary</a> which brings a continuous supply of hot, fresh magma up from the mantle just a few kilometres below. Icelanders have capitalised on this, and now generate more than a quarter of their electricity through <a href="http://www.nea.is/media/myndir/popup/Iceland_Leader_RenewableEnergy_Mynd.png">geothermal</a>, accessing boiling temperature water within 2km of the surface.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143297/original/image-20161026-11278-z24o5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Iceland is happy to exploit its unusual geology.</span>
<span class="attribution"><span class="source">Jose Arcos Aguilar / shutterstock</span></span>
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</figure>
<p>The <a href="http://iddp.is/">Iceland Deep Drilling Project</a> (IDDP) was set up to find out what happens at depths below 4km in the Icelandic crust. In 2009, during their first drilling leg, they accidentally <a href="https://theconversation.com/drilling-surprise-opens-door-to-volcano-powered-electricity-22515">hit a magma pocket</a>, and eventually stabilised the system to create the <a href="https://www.youtube.com/watch?v=3d8hC71xGpc">hottest steam</a> ever produced in geothermal exploration: 450°C. </p>
<p>The second borehole now being drilled aims to tap the deep circulating water which penetrates the rock around a magma chamber below the Reykjanes peninsula near Reykjavik.</p>
<h2>Follow the volcanoes</h2>
<p>The embarrassment of geothermal riches on offer in Iceland is unusual, but by no means unique. Indeed, while the country has one of the highest geothermal electricity productions in terms of total energy share, it is neither the highest, nor is it in the top five countries for total geothermal capacity. In fact, the countries in the top five may come as a surprise.</p>
<p>The absolute biggest geothermal electricity producer in the world is the US, <a href="https://pangea.stanford.edu/ERE/db/WGC/papers/WGC/2015/01001.pdf">with around 3,450 MW of capacity in 2015</a>, largely centred in California (a typical nuclear power station produces around 1,000 MW). Next up are the Philippines and Indonesia, at 1,870 and 1,340 MW respectively. Mexico and New Zealand trail at a little over 1,000 MW each, and Iceland (665 MW) comes in seventh behind Italy (916 MW). </p>
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<a href="https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=302&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=302&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=302&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=379&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=379&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143300/original/image-20161026-11265-10libvz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=379&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Geothermal energy will usually be found near active volcanoes.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Spreading_ridges_volcanoes_map-en.svg">Eric Gaba</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Volcanoes are the common factor in the geothermal resources of all these countries. The US has also utilised the enormous San Andreas fault zone and its ability to conduct heat and fluids through the crust.</p>
<h2>In search of the perfect geothermal site</h2>
<p>For geothermal energy to succeed there must be heat, it must be accessible, and you must be able to move water around it. These three simple requirements can be difficult to find together. </p>
<p>Across most of the planet the hot material is simply too deep down to be economically within reach. The temperature of the Earth’s crust generally increases by <a href="http://www.geologyin.com/2014/12/geothermal-gradient.html">25°C for every 1km depth</a>; for geothermal to be economical that value must be nearer 50 or even 150°C/km. That means you need to be near something geologically unusual: either thinned crust (so you’re closer to the hot mantle), or features such as plate boundaries or volcanoes which can direct heat or magma toward the surface.</p>
<p>If that condition is met you must still be able to move water around. Rocks are not all alike, as some can allow water to easily flow through the pores and boundaries between grains, while others are more like a barrier. If water cannot flow to the borehole then it cannot be brought to the surface. </p>
<p>If the hot area doesn’t have any natural water then engineers can pump some down. However, if the rocks prevent it flowing and dispersing then the water will simply cool the area immediately around the borehole, making it pointless in geothermal terms.</p>
<p>As with gold, rare-earth elements or good farmland, the geology of an area controls access to this valuable resource. Anywhere with active volcanoes could potentially benefit from the high temperature geothermal exploration being pioneered by the IDDP. That includes every country around the Pacific <a href="http://nationalgeographic.org/encyclopedia/ring-fire/">Ring of Fire</a> – an opportunity perhaps to extract some benefit from the volcanoes which dot their landscapes.</p><img src="https://counter.theconversation.com/content/67725/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pete Rowley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In Iceland, an audacious project to tap into magma deep below the surface may usher in a new era of geothermal power.Pete Rowley, Senior Scientific Officer, Earth Science, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.