Abstract
Growing evidence has demonstrated the importance of ice shelf buttressing on the inland grounded ice, especially if it is resting on bedrock below sea level. Much of the Southern Antarctic Peninsula satisfies this condition and also possesses a bed slope that deepens inland. Such ice sheet geometry is potentially unstable. We use satellite altimetry and gravity observations to show that a major portion of the region has, since 2009, destabilized. Ice mass loss of the marine-terminating glaciers has rapidly accelerated from close to balance in the 2000s to a sustained rate of -56 +/- 8 gigatons per year, constituting a major fraction of Antarctica's contribution to rising sea level. The widespread, simultaneous nature of the acceleration, in the absence of a persistent atmospheric forcing, points to an oceanic driving mechanism.
| Original language | English |
|---|---|
| Pages (from-to) | 899-903 |
| Number of pages | 5 |
| Journal | Science |
| Volume | 348 |
| Issue number | 6237 |
| DOIs | |
| Publication status | Published - 22 May 2015 |
Funding
B.W. and J.L.B. jointly conceived the study, interpreted the results, and wrote the article. B.W. processed the GRACE and Cryosat-2 L2 data. A.M.-E. combined the ICESat-Envisat elevation rates and derived the GVIIS front positions. V.H. developed the Cryosat-2 retracker and processed the L1B data. T.F. processed the Envisat data. J.M.v.W., S.R.M.L., and M.R.v.d.B. developed and ran the SMB and firn model. All authors commented on the manuscript. We thank J. Wahr and G. A for their help with the Glacial Isostatic Adjustment correction and elastic loading. G. Moholdt and A. Gardner are acknowledged for the fruitful discussions on altimetry. B.W. is funded by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (FP7-PEOPLE-2011-IOF-301260). J.L.B. and A.M.-E. were supported by Natural Environment Research Council grant NE/I027401/1. J.L.B., B.W., and A.M-E. also acknowledge support through European Space Agency contract 4000107393/12/I-NB, "REGINA." V.H. was supported by the German Ministry of Economics and Technology (grant 50EE1331). J.M.v.W., S.R.M.L., and M.R.v.d.B. acknowledge support from the Netherlands Polar Program of the Netherlands Organization for Scientific Research, section Earth and Life Sciences (NWO/ALW/NPP). The data sets used in this study can be found at http://pangaea.de.
Keywords
- AMUNDSEN SEA EMBAYMENT
- ICE-SHEET
- WEST ANTARCTICA
- MASS-BALANCE
- SHELF
- COLLAPSE
- RETREAT
- CRYOSAT-2
- DRIVEN
- WATERS
