tag:theconversation.com,2011:/africa/topics/ecuador-earthquake-26721/articlesEcuador earthquake – The Conversation2016-07-18T08:55:12Ztag:theconversation.com,2011:article/604962016-07-18T08:55:12Z2016-07-18T08:55:12ZEarthquake reveals the problems with Ecuador’s famous ‘good life’ policy<p>Disasters have a way of revealing the gap between what a government says it wants to do and what it actually does. As Oxfam’s Duncan Green <a href="https://oxfamblogs.org/fp2p/shocks-and-change/">put it</a>, disasters can bring to light some of the tensions, contradictions and strengths of a country’s political and development agenda.</p>
<p>So it went after <a href="http://www.nytimes.com/2016/05/19/world/americas/ecuador-earthquake.html?_r=0%22%22">Ecuador’s recent earthquake</a>, which not only represents the largest humanitarian but also the most significant housing crisis for the country since decades. More than 600 people died, thousands of people were injured and left homeless with their houses and surrounding infrastructure destroyed. </p>
<p>The earthquake uncovered some of the tensions between the government’s official ideas about development and its actual practices, which often ignore constitutional rights. It also revealed that while the government allegedly intends to cut ties with supposed ideological enemies such as the International Monetary Fund (IMF), it’s actually working to renew partnerships with the very same institutions. </p>
<p>Ecuador is renowned for its inclusive and participatory development model, which is known as “<a href="http://theconversation.com/buen-vivir-south-americas-rethinking-of-the-future-we-want-44507"><em>Buen Vivir</em></a>” (the good life). In a nutshell, <em>Buen Vivir</em> means that no one should live well if others live poorly, and that humans and nature should coexist in harmony. It is enshrined in <a href="http://pdba.georgetown.edu/Constitutions/Ecuador/english08.html">Ecuador’s 2008 constitution</a>, which also outlines a vast array of political, economic, social, and cultural rights. </p>
<p>These include collective indigenous rights, the right to nature, and the right to the city. The latter is the guideline for Ecuador’s sustainable and socially just urban development vision, according to which all urban residents are entitled to the full enjoyment of the city and its public spaces. </p>
<p>Citizens are meant to be directly involved in the design, implementation and evaluation of urban policy interventions. These should go beyond a singular focus on housing and infrastructure provisioning. Instead, urban policies ought to address diverse cultural, social, economic, and political interests of citizens, including those who have been historically marginalised such as the poor, women, children, people with disabilities, or ethnic minorities. </p>
<p>All well and good on paper, then – but in practice, things look rather different.</p>
<h2>A widening gap</h2>
<p>In recent years, indigenous rights and the right to nature have been <a href="http://www.theguardian.com/environment/2016/apr/04/ecuador-drills-for-oil-on-edge-of-pristine-rainforest-in-yasuni">blithely ignored</a> by the government, which has prioritised resource extraction over specific and supposedly sacrosanct constitutional rights. Urban development interventions have also rarely followed constitutional guidelines on the right to the city, but replicated and expanded the top-down and single sector practices of previous governments, namely housing subsidy schemes and large-scale social housing construction projects.</p>
<p>After the earthquake, this dissonance continued to play out in awkward ways. As a large number of houses had been destroyed, the government introduced <a href="http://www.andes.info.ec/es/noticias/gobierno-ecuador-anuncia-incentivos-socioeconomicos-acogida-vivienda-damnificados-terremoto">specific post-earthquake housing subsidies</a> and presented the first plans for <a href="http://www.elcomercio.com/actualidad/presentacion-proyecto-vivienda-damnificados-terremoto.html">a new social housing project for earthquake victims</a> which it will implement jointly with the Ecuadorian real estate giant Mutualista Pichincha. </p>
<p>These fast top-down, public-private interventions will certainly give shelter to some of those left homeless, but it’s unclear how they will reach those most in need, who might well find it difficult to access subsidy schemes or social housing units. And in the long term, it remains unclear whether and how the government will move to a more inclusive and holistic urban development approach that follows the constitution’s clear principles. </p>
<p>If it doesn’t, ordinary citizens will most likely not get a say in the reconstruction of earthquake-hit towns and cities, and the specific interests of those most in need will probably be omitted. </p>
<p>This tension was seized on by local urban activists in Quito in a post-earthquake <a href="https://geografiacriticaecuador.files.wordpress.com/2016/04/manifiesto.pdf">manifesto</a>, which called for an alternative, bottom-up national reconstruction and development agenda, one that protects all citizens’ rights to the city, including the recent earthquake’s victims.</p>
<h2>Hunkering down</h2>
<p>Implementing national development agendas often requires international support and alliance-building. Just as his left-leaning counterparts in Bolivia or Venezuela have done, Correa intended to <a href="http://uk.reuters.com/article/us-ecuador-election-debt-idUKN2342197220061123">sever Ecuador’s links</a> with international organisations such as the IMF or the World Bank and forge new alliances, both with countries such China and with regional organisations.</p>
<p>These new alliances were put to work in the immediate aftermath of the earthquake. Member states from the Union of South American Nations and the Bolivarian Alliance for the Peoples of our Americas were among the first to send rescuers, as well as financial and technical support. Government staff I recently interviewed in Quito particularly stressed the important role of Chile, a model state for earthquake response.</p>
<p>But the earthquake caught Ecuador at a moment of already serious financial dependency. A global drop in oil prices prior to the earthquake had already led to a decline of Ecuador’s oil revenue, an increase in debt (especially to China), and cuts in social spending. </p>
<p>On top of this economic and financial crisis, the earthquake caused approximately US$3 billion worth of damage. With only US$300m of emergency response money in place, the government sought further financial assistance and returned to the negotiation table not only with China but also with the Inter-American Development Bank (IDB), the World Bank and the IMF. By the end of April, a credit of US$600m was already <a href="http://www.reuters.com/article/us-ecuador-quake-idUSKCN0XP2VM">signed with the IDB and the World Bank</a>.</p>
<h2>Forging ahead</h2>
<p>The earthquake also gave the government a chance to push through some surprising reforms that have been deeply unpopular with entrenched, powerful interests. Days after the earthquake, it was <a href="http://www.independent.co.uk/news/world/americas/ecuador-to-tax-millionaires-to-pay-for-earthquake-reconstruction-a6994706.html">announced</a> that citizens with more than US$1m in assets must pay a one-time tax of 0.9% of their wealth, while those earning more than US$5,000 per month will have to contribute five days of their monthly pay to the government for earthquake recovery measures. </p>
<p>The government also <a href="http://www.elcomercio.com/actualidad/asamblea-aprobo-ley-ordenamiento-territorial.html">pushed through a law</a> to regulate territorial and land use management, and to introduce new measures for real estate taxes. In a country where wealth redistribution laws, tax reforms, real estate controls and local government oversight have all met <a href="http://www.wsj.com/articles/protesters-in-ecuador-demonstrate-against-correas-policies-1435279037">severe political resistance</a> from wealthier groups and local bureaucrats, these emergency reforms are a rare chance to redistribute resources to those most affected by the earthquake.</p>
<p>Even alongside all the unpalatable deal-making, the earthquake response can certainly be interpreted as a first step towards a more egalitarian and socially just type of development. But it’s still unclear just who will decide how the money raised will actually be spent. </p>
<p>And overall, it remains to be seen whether the government can actually make good on the constitution’s bottom-up, egalitarian ideals – or whether it’ll just continue with its top-down business as usual.</p><img src="https://counter.theconversation.com/content/60496/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philipp Horn 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>Ecuador is known for promoting the ‘Buen Vivir’ development policy agenda. But the state’s response to a recent earthquake brought its commitment into question.Philipp Horn, Postdoctoral research associate, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/579152016-04-22T10:52:26Z2016-04-22T10:52:26ZRemembering Nepal: a year on from the devastating earthquakes<figure><img src="https://images.theconversation.com/files/118908/original/image-20160415-11163-1upsy28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Villages across Nepal remain strewn with rubble, the quake victims still living in tents and flimsy sheds.</span> <span class="attribution"><span class="source">think4photop/Shutterstock</span></span></figcaption></figure><p>The recent earthquakes in <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us20005iis#general">Japan</a> and <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us20005j32#general">Ecuador</a> happened within hours of each other, killing <a href="http://www.bbc.co.uk/news/world-latin-america-36067380">several hundred people</a>. While both quakes were equally devastating for the countries and people involved, neither disaster has reached the scale experienced by Nepal last year.</p>
<p>On April 25 2015 Nepal experienced a magnitude <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us20002926#general">7.8 earthquake</a> that was followed 17 days later by a magnitude <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us20002ejl#general">7.3 earthquake</a>. More than 5m people were affected and <a href="http://www.undispatch.com/nepal-earthquake-facts-and-figures/">more than 8,500 killed</a>.</p>
<p>Between 1900 and 2015, there have been over <a href="over%202.5%20million%20fatalities%20due%20to%20earthquakes">2.5m fatalities</a> globally due to earthquakes, 30% of these have occurred since 2000. </p>
<p>The period 2000-2009 was the worst decade for earthquake fatalities on record, with more than half a million people killed. The current decade (2010-2019) is already on track to exceed that, with more than 350,000 people killed in earthquakes to date. </p>
<p>Of the five most deadly earthquakes in documented history, two have occurred since 2000; the <a href="http://www.ibtimes.co.uk/2004-indian-ocean-earthquake-tsunami-facts-1480629">2004 Indian Ocean earthquake</a> that killed more than a quarter of a million people and the catastrophic <a href="http://www.dec.org.uk/articles/haiti-earthquake-facts-and-figures">2010 Haiti earthquake</a> – which has the <a href="earthquake.usgs.gov/earthquakes/world/world_deaths.php">highest death toll</a> for an earthquake ever officially recorded (316,000). The 2000s also saw earthquakes in China, Pakistan, Iran and Japan take a combined total of more than 200,000 lives. </p>
<p>While the scale of these numbers is often shocking and highly emotive, it’s important that debates on the underlying science and appropriate mitigation are undertaken with care.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118940/original/image-20160415-11198-yx2ks.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">Ruined buildings in Kathmandu city after the earthquakes in Nepal.</span>
<span class="attribution"><span class="source">My good images/shutterstock</span></span>
</figcaption>
</figure>
<h2>Urban sprawl</h2>
<p>Global population growth and urbanisation, especially in Asia, is certainly one factor influencing the high death toll. Asia currently has the highest number of mega-cities in the world, most of which are growing fast, with some expected to grow by <a href="http://www.bloomberg.com/infographics/2014-09-09/global-megacities-by-2030.html">more than 46%</a> by 2030. </p>
<p>The number of people living in earthquake zones is now greater than ever before. This includes those living on the <a href="http://earthsky.org/earth/what-is-the-ring-of-fire">Pacific Ring of Fire</a> – a long chain of volcanoes and other active structures surrounding the Pacific Ocean – and along the <a href="http://ihrrblog.org/2012/06/04/new-research-project-earthquakes-without-frontiers/">Alpine-Himalayan belt</a>. This means earthquakes that would previously have killed hundreds now kill thousands or tens of thousands as a result of increased exposure.</p>
<p>But increased exposure is by no means the only factor. The adage that earthquakes don’t kill people buildings do, highlights a key challenge in increasing resilience to earthquakes. </p>
<p>The scale of the problem is apparent when we consider that <a href="link.springer.com/article/10.1007/s10518-006-9028-8">a 2007 study</a> estimated that 90% of buildings in Iran and Nepal – two countries known to have high earthquake risk – had limited earthquake safety. But this problem isn’t unique to Asia. The same study estimated 60-80% of buildings in Austria, which is notably <a href="http://www.conrad-observatory.at/cmsjoomla/en/seimology-overview/earthquakes-in-austria">earthquake prone</a>, were similarly vulnerable as a result of low earthquake awareness among professionals.</p>
<h2>Reducing the risk</h2>
<p>While the knowledge needed to construct earthquake safe buildings is available – even in some of the <a href="http://www.nset.org.np/nset2012/index.php/event/eventdetail/eventid-185">world’s poorest nations</a> – its implementation remains challenging. A combination of weak governance, limited capacity and resources leaves this task seemingly insurmountable. </p>
<p>This is further exacerbated because earthquake disasters in any one location are actually quite rare – before 2015, the previous major earthquake in Nepal was 81 years ago – and so memories of just how catastrophic earthquakes can be quickly fade.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118950/original/image-20160415-11167-bd9ynh.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">Population growth in earthquake zones is putting more lives at risk.</span>
<span class="attribution"><span class="source">dotshock/Shutterstock</span></span>
</figcaption>
</figure>
<p>Our <a href="https://www.dur.ac.uk/geography/staff/geogstaffhidden/?id=14083">research</a> is taking a new approach by using “scenarios” based on observations from previous events to simulate the hazards that result from an earthquake. These are then implemented using civilian or military simulations that help to test the abilities of first-responders during a disaster.</p>
<p>Scenarios are designed to simulate the consequences of an earthquake without having to experience one firsthand. They help to demonstrate the potential scale of earthquake impacts but also quantify how proposed mitigation – such as enforcing <a href="http://www.fema.gov/building-codes">earthquake safe building codes</a> – can have major positive effects. </p>
<p>By simulating changes to the current building stock, we can estimate how many lives could be saved as a result of efforts to increase resilience to earthquakes, for example. We know that buildings made from <a href="https://en.wikipedia.org/wiki/Adobe">mud brick and earth</a> are particularly vulnerable to earthquakes and replacing these could lead to substantial reductions in earthquake fatalities. </p>
<p>While our findings could aid decision makers, one criticism of this scenario approach is the focus upon a single event – which is by definition not the event that will happen next. However, we can explore multiple scenarios and assess where repeated losses recur – irrespective of the precise nature of each scenario tested. Major losses in different scenarios can then be identified and prioritised for mitigation. This approach allows us to consider how to address future earthquake losses, but it’s by no means a perfect solution. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119256/original/image-20160419-13895-34r4vi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&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 Ring of Fire, home to more than 450 active and dormant volcanoes.</span>
<span class="attribution"><a class="source" href="http://en.es-static.us/upl/2013/02/ring_of_fire_usgs_550.jpg">U.S. Geological Survey</a></span>
</figcaption>
</figure>
<p>In all earthquake prone nations seismic risks are just one of the many areas in need of investment. Consequently, it is often the nations with weak governance and the most limited resources that see the biggest loss to life from earthquakes. In these countries efforts to reduce such risks are superseded by the need to address livelihood demands such as clean water. </p>
<p>For countries like Nepal, where <a href="http://qz.com/392582/this-map-shows-where-the-strongest-earthquakes-are-expected-to-strike/">seismic risk</a> is considered to be particularly pervasive, this approach can help ensure earthquake risk is considered and prioritise where to deploy the limited resources that are available. </p>
<p>As well as this, we need to continue to explore new ways to make buildings more resilient to earthquakes, but this needs to be coupled with methods to make these efforts sustainable, cost effective, and prioritised by decision makers.</p>
<p>So while we can’t eliminate earthquake fatalities entirely, we can certainly work harder and smarter to reduce the losses and devastation that seem to go hand in hand when an earthquake hits.</p><img src="https://counter.theconversation.com/content/57915/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tom Robinson 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>Over 8,500 were killed in the 2015 Nepal earthquake, so how is the country coping?Tom Robinson, Junior Research Fellow in the Department of Geography, Durham UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/579782016-04-19T01:22:41Z2016-04-19T01:22:41ZAre the Japanese and Ecuador earthquakes related?<p>A <a href="http://www.abc.net.au/news/2016-04-15/strong-earthquake-hits-kyushu-japan-leaving-nine-dead/7328284">magnitude 6.5 earthquake struck Japan</a> on Friday, causing widespread injuries and property damage. Then on Saturday evening, a <a href="http://www.bbc.co.uk/news/world-latin-america-36067380">magnitude 7.8 earthquake hit Ecuador</a> on the other side of the Pacific, collapsing buildings and <a href="http://www.abc.net.au/news/2016-04-18/ecuador-earthquake-toll-certain-to-rise-president/7336136">killing more than 350 people</a>.</p>
<p>With two large earthquakes happening only days apart, it might look like they’re connected. But how earthquakes influence each other is rather complex, particularly over long distances.</p>
<h2>Aftershocks</h2>
<p>Large earthquakes are caused by the rupture of faults that are a few tens of kilometres long for magnitude 7, to more than 1,000 kilometres for magnitude 9 and above.</p>
<p>The local perturbations caused by the sudden shift of rock mass across a large rupture results in a cascade of smaller earthquakes, called aftershocks, at distances roughly equivalent to the length of initial fault rupture. Aftershock rates peak immediately following the mainshock and decay exponentially with time. </p>
<p>However, if nearby faults are locked and already stressed, more damaging earthquakes may be triggered in the short term. The 2004 Sumatra <a href="http://earthquake.usgs.gov/learn/topics/measure.php">magnitude</a> (Mw) 9.2 and 2005 Mw 8.6 Nias earthquakes are the best known examples of short-term “clustering” of very large quakes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=534&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=534&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=534&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=672&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=672&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119171/original/image-20160419-1269-982ee7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=672&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sumatran earthquake sequence for the 12 month period from 26/08/2004 to 25/08/2005 encompassing the 2004 Boxing Day Mw 9.2 and 2005 March Nias Mw 8.6 quakes. The y-axis shows each earthquake’s latitude. The initial 2004 Boxing Day ruptured some 1,300 kms northward from the initial rupture point near Banda Aceh (blue arrows), with aftershocks distributed all the way along the ruptured fault segment. The March 2005 Nias event ruptured an adjacent segment of the plate boundary to the south of the 2004 Boxing Day rupture, inducing a distinct aftershock sequence. In total almost 4,500 aftershocks of magnitude greater than 4 were recorded in the nine month period to late August 2005, of which about 560 were greater than 5. Note also how aftershock intensity tails off exponentially with time.</span>
<span class="attribution"><span class="source">Image by Mike Sandiford</span></span>
</figcaption>
</figure>
<p>A clear message from earthquake scientists to the public is that the most dangerous time for future large earthquakes in an affected region is immediately (within days to weeks) following a major earthquake. </p>
<p>The recent Nepal earthquakes in 2015 (Mw 7.8 and 7.3 within 17 days) provide further evidence for this. </p>
<p>Certainly, authorities in Ecuador, Panama, Colombia and Peru will be well aware of the importance of reiterating future hazards to the region posed by aftershocks, other strong earthquakes, tsunami, and other earthquake-triggered hazards in the aftermath of the Mw 7.8 earthquake on Saturday.</p>
<h2>Remotely triggered earthquakes</h2>
<p>But can earthquakes on one side of the globe trigger earthquakes on the other? And should we be concerned about the apparent global surge of earthquakes?</p>
<p>Large earthquakes send out seismic “shivers” that are recorded by seismographs around the globe. As these seismic surface waves pass through distant fault zones, they do occasionally trigger small earthquakes. </p>
<p>Scientists call this “remote triggering”. Some fault zones show evidence for “remote delayed triggering” several hours after the seismic surface waves from a large remote event pass through. However, a <a href="http://www.sciencedirect.com/science/article/pii/S0040195114000742">recent analysis</a> indicates no compelling evidence for triggered events exceeding magnitude 5. </p>
<p>How long is too long before a local increase in earthquake activity can be linked to a preceding quake? </p>
<p>Therein lies a challenge that transcends seismic catalogues alone, requiring both rigorous statistical analysis and an analysis of the geologic conditions that could favour long time delays. </p>
<p>What we do know is that the transient stresses induced by large earthquakes are very small at remote distances, but perhaps not too small to influence the frequency of earthquakes in other regions. </p>
<p>What we also know is that the rate of global earthquakes is not steady. For example, the rate of large earthquakes since 2004 is more than double the rate averaged over the preceding century. </p>
<p>A similar cluster of large global earthquakes occurred between 1950 and 1965. To date, the reasons for the apparent multidecadal changes in seismic energy release rate remain poorly understood.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=357&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=357&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=357&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=449&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=449&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119076/original/image-20160418-1504-jwkzpl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=449&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This map shows all earthquakes with a magnitude over 4.5 from the 11th-18th April. You can see that many earthquakes occurred around the Pacific during that period, but there are clusters around Japan and Ecuador following the large earthquakes there.</span>
<span class="attribution"><a class="source" href="http://earthquake.usgs.gov/earthquakes/map/">USGS</a></span>
</figcaption>
</figure>
<h2>Japan and Ecuador</h2>
<p>The April 15, 2016, Mw 7.0 Japanese earthquake occurred as the result of <a href="http://www.britannica.com/science/strike-slip-fault">strike-slip faulting</a>. It was centred around 10km depth and ruptured an area around 50km long. </p>
<p>Effects of the Japanese earthquake include landslides, <a href="http://earthquake.usgs.gov/learn/glossary/?term=liquefaction">liquefaction</a>, ground failure and building damage.</p>
<p>It was similar in style and dimensions of rupture and shaking to the <a href="http://www.drquigs.com/wp-content/uploads/2016/03/TECTONO.pdf">2010 Mw 7.1 Darfield earthquake near Christchurch New Zealand</a>. </p>
<p>Aftershocks pose a major hazard, particularly to structures compromised by prior shaking. However, the Japanese earthquake occurred in a region that is frequently affected by seismic shaking from strong earthquakes, so the occurrence of this event should be no real surprise.</p>
<p>The April 16, 2016, Mw 7.8 earthquake offshore of the west coast of northern Ecuador occurred as the result of shallow <a href="http://earthquake.usgs.gov/learn/glossary/?term=dip%20slip">thrust faulting</a> on or near the plate boundary between the subducting Nazca and overriding South American tectonic plates. </p>
<p>The location and mechanism of the earthquake is consistent slip on the large thrust fault (i.e. <a href="https://en.wikipedia.org/wiki/Megathrust_earthquake">megathrust</a>), between these two major plates. The rupture length is estimated at 160km. </p>
<p>Earthquakes of this nature are relatively common in this region, even over historical timescales. The same plate boundary zone extending all the way along the western boundary of South America has produced <a href="https://en.wikipedia.org/wiki/1960_Valdivia_earthquake">the 1960 Valdivia quake</a> – the largest ever recorded – and so again its rupture in Ecuador should be no particular surprise. </p>
<p>Any dynamic stresses induced by the Japanese earthquake at the site of the impending earthquake on the subduction zone west of Ecuador would pale in comparison to the local stresses accumulated from subduction of the Nazca plate, the relevant segment of which <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us20005j32#general">last ruptured in a large earthquake in 1942</a>. </p>
<p>So the Japanese and Ecuador earthquakes were both large and damaging, and they occurred only days apart. This naturally triggers a great deal of media attention, and it’s easy to assume there is a link.</p>
<p>But the time delay between the Japanese and Ecuador events precludes any clear causal linkage on temporal grounds. Rather they are the natural consequence of the ongoing activity that surrounds the Pacific basin, in the so-called “ring of fire”, during a period of somewhat heightened seismic energy release.</p><img src="https://counter.theconversation.com/content/57978/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Quigley has received funding from the New Zealand Earthquake Commission for his research. </span></em></p><p class="fine-print"><em><span>Mike Sandiford receives funding from the Australian research Council for research into the young geological activity in the Indo-Australian tectonic plate.</span></em></p>When two major earthquakes occur within days of each other thousands of kilometres apart, it can look like they’re connected. But are they? Here’s what the science says.Mark Quigley, Associate professor, The University of MelbourneMike Sandiford, Professor of Geology, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.