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Climatic warming and basal melting of large ice sheets: Possible implications for east Antarctica
Author(s) -
Saari Marc R.,
Yuen David A.,
Schubert Gerald
Publication year - 1987
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl014i001p00033
Subject(s) - instability , ice sheet , geology , antarctic ice sheet , ice stream , ice sheet model , climatology , sea ice growth processes , ice core , atmospheric sciences , oceanography , cryosphere , antarctic sea ice , sea ice , mechanics , physics
Climatic warming is shown to be capable of inducing shear heating instability and basal melting in a model ice sheet that is creeping slowly downslope. Growth times of the instability are calculated from a nonlinear analysis of temperature and flow in the model ice sheet whose surface undergoes a prescribed increase of temperature. The source of instability lies in the decrease of maximum ice thickness for steady downslope creep with increasing surface temperature. A surface temperature increase of 5 to 10 K can cause instability on a 10 4 year time scale for realistic ice rheology. The instability occurs suddenly after a prolonged period of dormancy. The instability might be relevant to the East Antarctic ice sheet. Warming associated with the Holocene interglacial epoch that heralded the end of the last ice age may have set the East Antarctic ice sheet on a course toward widespread instability some 10 4 years later. The present CO 2 ‐induced climate warming is also a potential trigger for instability and basal melting of the East Antarctic ice sheet.