Climatic warming and basal melting of large ice sheets: possible implications for East Antarctica
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/sup 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 wide-spread instability some 10/sup 4/ years later. The present CO/sub 2/-induced climate warming is also a potential trigger for instability and basal melting of the East Antarctic ice sheet.
- Research Organization:
- Arizona State Univ., Tempe
- OSTI ID:
- 6027747
- Journal Information:
- Geophys. Res. Lett.; (United States), Vol. 14:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
CARBON DIOXIDE
ENVIRONMENTAL EFFECTS
CLIMATES
VARIATIONS
ICE CAPS
MELTING
AMBIENT TEMPERATURE
ANTARCTICA
FLOW RATE
GREENHOUSE EFFECT
QUATERNARY PERIOD
ANTARCTIC REGIONS
CARBON COMPOUNDS
CARBON OXIDES
CENOZOIC ERA
CHALCOGENIDES
GEOLOGIC AGES
ICE
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POLAR REGIONS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
580100 - Geology & Hydrology- (-1989)