Is the West Antarctic Ice Sheet Disintegrating?
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Material Information

Title:
Is the West Antarctic Ice Sheet Disintegrating?
Series Title:
Journal of Geophysical Research Volume 78 Number 33
Creator:
Hughes, T.
Publisher:
American Geophysical Union
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Climate Change ( lcsh )
Ice Sheets ( lcsh )
Antarctica ( lcsh )
Ice Age ( lcsh )

Notes

Abstract:
Data pertaining to the dynamics and history of the west antarctic ice cover are reviewed and interpreted in terms of a possible inherent instability of the ice cover. A study of published dat• concerning the past and present ice cover of West Antarctica indicates that during the last few million years the ice sheet has been retreating in stages, each retreat stage being preceded by an advance of comparable duration. Thus disintegration of the west antarctic ice sheet seemst o follow the disintegrationp attern of other continentali ce sheetsa nd may be the last phase of the wo.rldwide Late Cenozoic ice age. At least some of the retreat stages seem to have been rapid enough to be called surges. Stages of advance seem to have temporarily introduced equilibrium conditions, since equilibrium ice sheet surface profiles can be reconstructedfr om the moraines,e tc., and thus mark the stable limits of each advance. Present ice sheet surface profiles along flowlines entering both the Ronne and the Ross ice shelvesf rom Marie Byrd Land are not equilibrium profiles,s uggestingth at the west antarctic ice sheet is unstable. An analysis of the grounded portion of the west antarctic ice cover indicates that data relating to the surface profile, ice velocity, and the mass balance are all incompatible with an equilibrium ice sheet. Instability seems to be centered in the major ice streams that drain Marie Byrd Land. An analysis of the floating portion of the west antarctic ice cover indicates that basal melting is most pronounced along the Siple Coast of the Ross ice shelf and causes retreat of the grounding line into Marie Byrd Land. Instability seems to be related to sudden retreats of the grounding line. ( English )

Record Information

Source Institution:
Florida International University
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