A paleooceanographer describes her ninth sea expedition, this time retrieving cylindrical 'cores' of the sediment and rock that's as much as two miles down at the ocean floor.
The sediments that accumulate beneath seagrass meadows can act as secure vaults for shipwrecks and other precious artefacts, by stopping water and oxygen from damaging the delicate timbers.
Coal dust and oil can spread toxic chemicals hundreds of kilometres out to sea. But Australia's monitoring guidelines do not meet the standards used in countries such as the United States.
Marine sediments provide evidence of climate variability in South Africa going back 270,000 years. These changes correspond with changes in the archaeological record of the country.