Geothermal Heat Flow and its Influence at the Base of Ice Sheets
Abstract
Future sea-level change primarily depends on the amount of ice mass loss in polar regions, which, in turn, depends on the conditions at the base of ice sheets. The thermal conditions are important because of widespread water beneath Greenland and Antarctica, affecting both ice dynamics and mass budget. Melting or freezing at the base of ice sheets depends on the heat balance. This includes geothermal heat flow, heat conducted or advected through the ice sheet, latent heat, and friction heat at the rock-ice interface. Geothermal heat flow is one of the least known parameters affecting ice sheets and it depends on geological factors such as mantle heat flow, crustal heat production and tectonic history. This parameter interacts with the base of ice sheets from thousands to billions of years, and from local to continental scales. Here, the Antarctic and Greenland wide geothermal heat flow models are discussed with special emphasis on magnetically derived ones. The new inferred heat flow distributions for the Antarctic and Greenland are helping us to unveil more details about the subglacial geology and lithospheric state as well as their geodynamic history. In addition, and considering the latest geothermal heat flow models, a discussion of the thermal conditions at the base of the ice sheets is presented for both Antarctica and Greenland. For Greenland, radar bed-echoes are discussed to better understand the basal water distribution of the ice sheet and the relation to geothermal heat flow. For Antarctica, basal temperatures and melt rates are presented to understand the influence of geothermal heat flow on these crucial thermal conditions for ice sheet dynamics.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C14B..01M
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 0774 Dynamics;
- CRYOSPHERE;
- 1209 Tectonic deformation;
- GEODESY AND GRAVITY;
- 8124 Earth's interior: composition and state;
- TECTONOPHYSICS