Dynamics of the West Antarctic Ice Sheet

Few scientists doubt the prediction that the antropogenic release of carbon dioxide in the atmosphere will lead to some warming of the earth's climate. So there is good reason to investigate the possible effects of such a warming, in dependence of geographical and social­ economic setting. Many bodies, governmental or not, have organized meetings and issued reports in which the carbon dioxide problem is defined, reviewed, and possible threats assessed. The rate at which such reports are produced still increases. However, while more and more people are getting involved in the 'carbon dioxide business', the number of investigators working on the basic problems grows, in our view, too slowly. Many fundamental questions are still not answered in a satisfactory way, and the carbon dioxide building rests on a few thin pillars. One such fundamental question concerns the change in sea level associated with a climatic warming of a few degrees. A number of processes can be listed that could all lead to changes of the order of tens of centimeters (e. g. thermal expansion, change in mass balance of glaciers and ice sheets). But the picture of the carbon dioxide problem has frequently be made more dramatic by suggesting that the West Antarctic Ice Sheet is unstable, implying a certain probability of a 5 m higher sea-level stand within a few centuries.

Contenu

The West Antarctic Ice Sheet: the need to understand its dynamics.- Force budget of ice sheets.- On the oceanic circulation near a shelf-ice edge.- Quantitative estimates of the mass flux and ice movement along the ice edges in the eastern and southern Weddell Sea.- Some aspects of the flow of the Ronne Ice Shelf.- Unconfined ice-shelf flow.- Plane and radial ice-shelf flow with prescribed temperature profile.- Ice-shelf backpressure: form drag versus dynamic drag.- Ice stream-ice shelf interaction in West Antarctica.- A few preliminary results from the glaciogeophysical survey of the interior Ross Embayment (GSIRE).- On the flow within the transition zone between ice sheet and ice shelf.- The finite-element method applied to a time-dependent flowband model.- Longitudinal stresses and basal sliding: a comparative study.- A subglacial aquifer bed model and water pressure dependent basal sliding relationship for a West Antarctic ice stream.- The heat budget of the Ross drainage basin.- Numerical modelling of the large-scale basal water flux under the West Antarctic Ice Sheet.- Modelling the response of the West Antarctic Ice Sheet to a climatic warming.- Geographic index.