Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch

摘要

The stability of the Antarctic ice shelves in a warming climate has long been discussed(1), and the recent collapse of a significant part, over 12,500 km(2) in area, of the Larsen ice shelf off the Antarctic Peninsula(2,3) has led to a refocus toward the implications of ice shelf decay for the stability of Antarctica's grounded ice(4-6). Some smaller Antarctic ice shelves have undergone periodic growth and decay over the past 11,000 yr ( refs 7 - 11), but these ice shelves are at the climatic limit of ice shelf viability(12) and are therefore expected to respond rapidly to natural climate variability at century to millennial scales(8-11). Here we use records of diatoms, detrital material and geochemical parameters from six marine sediment cores in the vicinity of the Larsen ice shelf to demonstrate that the recent collapse of the Larsen B ice shelf is unprecedented during the Holocene. We infer from our oxygen isotope measurements in planktonic foraminifera that the Larsen B ice shelf has been thinning throughout the Holocene, and we suggest that the recent prolonged period of warming in the Antarctic Peninsula region(13,14), in combination with the long-term thinning, has led to collapse of the ice shelf.