scholarly journals Did the West Antarctic Ice Sheet Create the East Antarctic Ice Sheet?

1982 ◽  
Vol 3 ◽  
pp. 138-145 ◽  
Author(s):  
T. J. Hughes

The mostly terrestrial East Antarctic ice sheet is ten times larger and probably more stable than the mostly marine West Antarctic ice sheet. It is natural to suppose that the former appeared first, and that perhaps the latter was partially formed from an outflow of East Antarctic ice onto the West Antarctic continental shelf. Alternatively, the largely marine West Antarctic ice sheet may have appeared first, provided that post-Eocene continental drift allowed heavy snow precipitation over the West Antarctic island archipelago, but prevented warm South Pacific ocean currents from entering. Sea ice could then thicken and ground from surface accumulation and basal freezing, creating broad marine ice domes in shallow West Antarctic embayments. These marine ice domes could then merge with ice caps on the islands to create a marine ice sheet that could expand into East Antarctica and merge with highland ice caps to form the terrestrial East Antarctic ice sheet. A Cenozoic glacial history of Antarctica is outlined, based on this marine ice transgression hypothesis.

1982 ◽  
Vol 3 ◽  
pp. 138-145 ◽  
Author(s):  
T. J. Hughes

The mostly terrestrial East Antarctic ice sheet is ten times larger and probably more stable than the mostly marine West Antarctic ice sheet. It is natural to suppose that the former appeared first, and that perhaps the latter was partially formed from an outflow of East Antarctic ice onto the West Antarctic continental shelf. Alternatively, the largely marine West Antarctic ice sheet may have appeared first, provided that post-Eocene continental drift allowed heavy snow precipitation over the West Antarctic island archipelago, but prevented warm South Pacific ocean currents from entering. Sea ice could then thicken and ground from surface accumulation and basal freezing, creating broad marine ice domes in shallow West Antarctic embayments. These marine ice domes could then merge with ice caps on the islands to create a marine ice sheet that could expand into East Antarctica and merge with highland ice caps to form the terrestrial East Antarctic ice sheet. A Cenozoic glacial history of Antarctica is outlined, based on this marine ice transgression hypothesis.


Geology ◽  
2010 ◽  
Vol 38 (5) ◽  
pp. 411-414 ◽  
Author(s):  
Michael J. Bentley ◽  
Christopher J. Fogwill ◽  
Anne M. Le Brocq ◽  
Alun L. Hubbard ◽  
David E. Sugden ◽  
...  

1994 ◽  
Vol 20 ◽  
pp. 336-340 ◽  
Author(s):  
Philippe Huybrechts

A model of the Antarctic ice sheet has been used to simulate the ice sheet in warmer climates, in order to investigate what kind of ice-sheet geometries one can reasonably expect under what kind of climatic conditions and to discover which physical mechanisms may be involved to explain them. The results of these experiments reveal the considerable stability of; in particular, the East Antarctic ice sheet. It would require a temperature rise of between 17 and 20 K above present levels to remove this ice sheet from the subglacial basins in the interior of the continent and of 25 K to melt down the Antarctic ice sheet completely. For a temperature rise below 5 K, the model actually predicts a larger Antarctic ice sheet than today as a result of increased snowfall, whereas the west Antarctic ice sheet was round not to survive temperatures more than 8–10 K above present values. Furthermore, basal temperature conditions in these experiments point to the problems involved in raising the base of the ice sheet to the pressure-melting point over the large areas necessary to consider the possibility of sliding instability. These results bear on a lively debate regarding the late Cenozoic glacial history of Antarctica. Particularly, based on these findings, it is difficult to reconcile a highly variable East Antarctic ice sheet until the Pliocene with modest warming recorded in, for instance, the deep-sea records for the late Neogene.


Geology ◽  
2011 ◽  
Vol 39 (5) ◽  
pp. e240-e240 ◽  
Author(s):  
Michael J. Bentley ◽  
David E. Sugden ◽  
Christopher J. Fogwill ◽  
Anne M. Le Brocq ◽  
Alun L. Hubbard ◽  
...  

1994 ◽  
Vol 20 ◽  
pp. 336-340 ◽  
Author(s):  
Philippe Huybrechts

A model of the Antarctic ice sheet has been used to simulate the ice sheet in warmer climates, in order to investigate what kind of ice-sheet geometries one can reasonably expect under what kind of climatic conditions and to discover which physical mechanisms may be involved to explain them. The results of these experiments reveal the considerable stability of; in particular, the East Antarctic ice sheet. It would require a temperature rise of between 17 and 20 K above present levels to remove this ice sheet from the subglacial basins in the interior of the continent and of 25 K to melt down the Antarctic ice sheet completely. For a temperature rise below 5 K, the model actually predicts a larger Antarctic ice sheet than today as a result of increased snowfall, whereas the west Antarctic ice sheet was round not to survive temperatures more than 8–10 K above present values. Furthermore, basal temperature conditions in these experiments point to the problems involved in raising the base of the ice sheet to the pressure-melting point over the large areas necessary to consider the possibility of sliding instability. These results bear on a lively debate regarding the late Cenozoic glacial history of Antarctica. Particularly, based on these findings, it is difficult to reconcile a highly variable East Antarctic ice sheet until the Pliocene with modest warming recorded in, for instance, the deep-sea records for the late Neogene.


2011 ◽  
Vol 75 (3) ◽  
pp. 417-429 ◽  
Author(s):  
Katherine Pingree ◽  
Max Lurie ◽  
Terence Hughes

AbstractThe Greenland and East and West Antarctic ice sheets are assessed as being the source of ice that produced an Eemian sea level 6 m higher than present sea level. The most probable source is total collapse of the West Antarctic Ice Sheet accompanied by partial collapse of the adjacent sector of the East Antarctic Ice Sheet in direct contact with the West Antarctic Ice Sheet. This conclusion is reached by applying a simple formula relating the “floating fraction” of ice along flowlines to ice height above the bed. Increasing the floating fraction lowered ice elevations enough to contribute up to 4.7 m to global sea level. Adding 3.3 m resulting from total collapse of the West Antarctic Ice Sheet accounts for the higher Eemian sea level. Partial gravitational collapse that produced the present ice drainage system of Amery Ice Shelf contributes 2.3 m to global sea level. These results cast doubt on the presumed stability of the East Antarctic Ice Sheet, but destabilizing mechanisms remain largely unknown. Possibilities include glacial surges and marine instabilities at the respective head and foot of ice streams.


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