Science Café: Ash Ice Mud: Tephras and Rapid Climate Change
Dylan Thomas Centre
Abrupt climate changes have occurred in the past, heating the planet by up to 16˚C in a few decades causing major environmental impacts on the face of the Earth. These shifts are thought to have involved a strong interplay between the ocean circulation and atmospheric dynamics, yet the mechanisms that drove these processes are poorly understood. To prepare ourselves for the future, a team of scientists led by Professor Siwan Davies from the Department of Geography, Swansea University investigate the evidence of past events that remain buried deep within Arctic ice and mud from the sea-bed. They search for microscopic traces of volcanic ash, in order to help understand the mechanisms that drove these sudden climate shifts. As each volcanic ash has a distinct geochemical fingerprint, this allows us to use these as tie-lines between the ice and marine records. These then permit a comparison of atmospheric dynamics (preserved within the ice) and the ocean circulation (preserved within marine mud) and will boost our understanding of the cause-and-effect relationship between large-scale changes in both atmospheric and sea temperatures. Recent work has uncovered the fact that these invisible layers of volcanic ash have a wide geographical reach, just as we saw with the 2010 Icelandic ash cloud distribution. Work by this team has also revealed several previously undocumented eruptions and allow us to link and compare the North Atlantic marine records with the Greenland ice-core records.
The Swansea Science Café offers opportunities for anyone to find out more about new, exciting and topical areas of science. Designed to be informal and entertaining, entry is free and talks start at 7:30 pm at the Dylan Thomas Centre. http://www.swansea.ac.uk/science/swanseasciencecafe/