Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: Constraints on past ice volume change

The retreat history of the West Antarctic Ice Sheet (WAIS) since the Last Glacial Maximum is important for understanding the process of rapid deglaciation, constraining models that seek to predict the future trajectory of the ice sheet, and for estimating rates of sea-level change. Here we report new glacial geologic data from the southwestern Weddell Sea embayment that demonstrate that this part of the WAIS was thinner than previously suggested, and that there was progressive thinning of the ice sheet by 230–480 m since ca. 15 ka. We use geomorphological data and a numerical ice sheet model to reconstruct the ice sheet in the Weddell Sea at the Last Glacial Maximum. The volume of this ice would have added between 1.4 and 2.0 m to postglacial sea-level rise and would not have been sufficient to contribute significantly to meltwater pulse 1A, a rapid rise in sea level ∼14,200 yr ago.

[1]  E. Ivins,et al.  Antarctic glacial isostatic adjustment: a new assessment , 2005, Antarctic Science.

[2]  G. Denton,et al.  Radiocarbon chronology of ross sea drift, eastern taylor valley, antarctica: evidence for a grounded ice sheet in the ross sea at the last glacial maximum , 2000 .

[3]  K. Lambeck,et al.  Refining the eustatic sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites , 1998 .

[4]  G. Milne,et al.  Modelling Antarctic sea-level data to explore the possibility of a dominant Antarctic contribution to meltwater pulse IA , 2007 .

[5]  M. J. Bentley.  Volume of Antarctic Ice at the Last Glacial Maximum, and its impact on global sea level change , 1999 .

[6]  J. Bockheim,et al.  Chapter 22: Glacial history of the Ellsworth Mountains, West Antarctica , 1992 .

[7]  Richard B. Alley,et al.  Decoding the dipstick: Thickness of Siple Dome, West Antarctica, at the Last Glacial Maximum , 2005 .

[8]  Peter J. Bradbury,et al.  The Last Glacial Maximum , 2009, Science.

[9]  D. Sugden,et al.  Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last interglacial? , 2012 .

[10]  Hall,et al.  Past and Future Grounding-Line Retreat of the West Antarctic Ice Sheet. , 1999, Science.

[11]  W. Peltier.  GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .

[12]  P. Clark.  Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: Constraints on past ice volume change: COMMENT , 2011 .

[13]  S. Price,et al.  Evidence for late Pleistocene thinning of Siple Dome, West Antarctica , 2007 .

[14]  G. Miller,et al.  Cosmogenic radionuclides from fiord landscapes support differential erosion by overriding ice sheets , 2006 .

[15]  D. Hodgson,et al.  Relative sea-level history from the Lambert Glacier region, East Antarctica, and its relation to deglaciation and Holocene glacier readvance , 2005, Quaternary Research.

[16]  P. Clark,et al.  Sea-Level Fingerprinting as a Direct Test for the Source of Global Meltwater Pulse IA , 2002, Science.

[17]  A. Payne,et al.  The Glimmer community ice sheet model , 2009 .

[18]  G. Denton,et al.  Reconstructing the Antarctic Ice Sheet at the Last Glacial Maximum. , 2002 .

[19]  J. Okuno,et al.  Late Pleistocene and Holocene melting history of the Antarctic ice sheet derived from sea-level variations , 2000 .

[20]  D. Sugden,et al.  Geomorphological evidence and cosmogenic 10Be/26Al exposure ages for the Last Glacial Maximum and deglaciation of the Antarctic Peninsula Ice Sheet , 2006 .

[21]  W. Peltier.  On the hemispheric origins of meltwater pulse 1a , 2005 .

[22]  Philippe Huybrechts,et al.  Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles , 2002 .

[23]  D. Sugden,et al.  Cosmogenic nuclides 10Be and 26Al imply limited Antarctic Ice Sheet thickening and low erosion in the Shackleton Range for >1 m.y. , 2004 .

[24]  K. Licht.  The Ross Sea's contribution to eustatic sea level during meltwater pulse 1A , 2004 .

[25]  E. Boyle,et al.  Deglacial meltwater discharge, North Atlantic Deep Circulation, and abrupt climate change , 1991 .

[26]  B. Tapley,et al.  Antarctic mass rates from GRACE , 2006 .

[27]  P. Fanning,et al.  Exposure ages from mountain dipsticks in Mac. Robertson Land, East Antarctica, indicate little change in ice-sheet thickness since the Last Glacial Maximum , 2007 .

[28]  M. Caffee,et al.  Holocene Deglaciation of Marie Byrd Land, West Antarctica , 2001, Science.

[29]  G. Miller,et al.  Preservation of Arctic landscapes overridden by cold-based ice sheets , 2006, Quaternary Research.

[30]  C. Ritz,et al.  Evolution of the Antarctic ice sheet throughout the last deglaciation: A study with a new coupled climate—north and south hemisphere ice sheet model , 2006 .

[31]  J. Stone,et al.  Late Quaternary evolution of Reedy Glacier, Antarctica , 2010 .

[32]  John B. Anderson,et al.  Radiocarbon constraints on Antarctic Peninsula Ice Sheet retreat following the Last Glacial Maximum (LGM) , 2007 .

[33]  John B. Anderson,et al.  The Antarctic Ice Sheet during the Last Glacial Maximum and its subsequent retreat history: a review , 2002 .

[34]  D. Sugden,et al.  Selective glacial erosion and weathering zones in the coastal mountains of Marie Byrd Land, Antarctica , 2005 .

[35]  John B. Anderson,et al.  Glacial and marine geological evidence for the ice sheet configuration in the Weddell Sea–Antarctic Peninsula region during the Last Glacial Maximum , 1998, Antarctic Science.