Radiocarbon dates of tiny fossilised marine animals found in Antarctica's seabed sediments offer new clues about the recent rapid ice loss from the West Antarctic Ice Sheet and help scientists make better predictions about future sea-level rise. This region of the icy continent is thought to be vulnerable to regional climate warming and changes in ocean circulation.
Reporting this month in the journal Geology a team of researchers from British Antarctic Survey (BAS), the Alfred Wegener Institute for Polar and Marine Research (AWI) and the University of Troms presents a timeline for ice loss and glacier retreat in the Amundsen Sea region of West Antarctica. The team concludes that the rapid changes observed by satellites over the last 20 years at Pine Island and Thwaites glaciers may well be exceptional and are unlikely to have happened more than three or four times in the last 10,000 years.
This study is part of an urgent international effort by polar scientists to understand if the recent rapid changes are unusual in the geological past.
The team studied the average rate of glacial retreat since the end of the last Ice Age around 12,000 years ago. Their work centred on Pine Island and Thwaites glaciers, which drain ice from the West Antarctic Ice Sheet into Pine Island Bay.
Lead author Dr Claus-Dieter Hillenbrand from BAS says,
"As snow and ice builds up on the vast Antarctic Ice Sheet, the ice flows from the centre of the continent through glaciers towards the sea where it often forms floating ice shelves and eventually breaks off as icebergs. The floating ice shelves hold back the ice on land. A critical issue for us is to understand how the 'grounding line' the position where the ice sitting on land (glaciers) begins to float (ice shelves) has retreated landward over time. Satellite data are available only for the last 20 years and show that since 1992 the Pine Island and Thwaites glaciers hav
|Contact: Paul Seagrove|
British Antarctic Survey