Effect of Sedimentation on Ice-Sheet Grounding-Line Stability

Sedimentation filling space beneath ice shelves helps to stabilize ice sheets against grounding-line retreat in response to a rise in relative sea level of at least several meters. Recent Antarctic changes thus cannot be attributed to sea-level rise, strengthening earlier interpretations that warming has driven ice-sheet mass loss. Large sea-level rise, such as the ≈100-meter rise at the end of the last ice age, may overwhelm the stabilizing feedback from sedimentation, but smaller sea-level changes are unlikely to have synchronized the behavior of ice sheets in the past.

[1]  Mark F. Meier,et al.  Fast tidewater glaciers , 1987 .

[2]  Sridhar Anandakrishnan,et al.  Discovery of Till Deposition at the Grounding Line of Whillans Ice Stream , 2007, Science.

[3]  T. Scambos,et al.  Glacier acceleration and thinning after ice shelf collapse in the Larsen B embayment, Antarctica , 2004 .

[4]  Matt A. King,et al.  Ice stream D flow speed is strongly modulated by the tide beneath the Ross Ice Shelf , 2003 .

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

[6]  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 .

[7]  S. Jacobs,et al.  Rapid Bottom Melting Widespread near Antarctic Ice Sheet Grounding Lines , 2002, Science.

[8]  Elsa Cortijo,et al.  Millennial‐scale iceberg discharges in the Irminger Basin during the Last Glacial Period: Relationship with the Heinrich events and environmental settings , 1998 .

[9]  Richard B. Alley,et al.  Ice thickness and isostatic imbalances in the Ross Embayment, West Antarctica: model results , 2004 .

[10]  Johannes Weertman,et al.  Stability of the junction of an ice sheet and an ice shelf , 1974 .

[11]  Sridhar Anandakrishnan,et al.  Outburst flooding and the initiation of ice-stream surges in response to climatic cooling: A hypothesis , 2006 .

[12]  Richard B. Alley,et al.  Assessment of the importance of ice‐shelf buttressing to ice‐sheet flow , 2005 .

[13]  S. Anandakrishnan,et al.  Static grounding lines and dynamic ice streams: Evidence from the Siple Coast, West Antarctica , 2006 .

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

[15]  John B. Anderson,et al.  The death mask of the antarctic ice sheet: Comparison of glacial geomorphic features across the continental shelf , 2006 .

[16]  D. Schrag,et al.  The Salinity, Temperature, and δ18O of the Glacial Deep Ocean , 2002, Science.

[17]  John B. Anderson,et al.  Expansion and rapid retreat of the West Antarctic Ice Sheet in eastern Ross Sea: possible consequence of over-extended ice streams? , 2006 .