The glacial history of the Antarctic is currently one of the most important topics in climate research. Why? Because worsening climate change raises a key question: How did the ice masses of the southern continent react to changes between cold and warm phases in the past, and how will they do so in the future? A team of international experts, led by geophysicists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), has now shed new light on nine pivotal intervals in the climate history of the Antarctic, spread over 34 million years, by reconstructing the depth of the Southern Ocean in each one. These new maps offer insights into e.g. the past courses of ocean currents, and show that, in past warm phases, the large ice sheets of East Antarctica reacted to climate change in a similar way to how ice sheets in West Antarctica are doing so today. The maps and the freely available article have just been released in the online journal Geochemistry, Geophysics, Geosystems, a publication of the American Geological Union.
The Southern Ocean is one of the most important pillars of the Earth’s climate system. Its Antarctic Circumpolar Current, the most powerful current on the planet, links the Pacific, Atlantic and Indian Oceans, and has effectively isolated the Antarctic continent and its ice masses from the rest of the world for over 30 million years. Then and now, ocean currents can only flow where the water is sufficiently deep and there are no obstacles like land bridges, islands, underwater ridges and plateaus blocking their way. Accordingly, anyone seeking to understand the climate history and glacial history of the Antarctic needs to know exactly what the depth and surface structures of the Southern Ocean’s floor looked like in the distant past.
Read more at: Alfred Wegener Institute