Constraining Geothermal Flux At Coastal Domes Of The Ross Ice Sheet, Antarctica

The geothermal flux is an important boundary condition for ice-sheet models because it influences whether the ice is melting at the bed and able to slide. Point measurements and remotely sensed estimates vary widely for the Ross Ice Sheet. A basal temperature measurement at Roosevelt Island reveals a geothermal flux of 84 +/- 13 mW/m(2). The presence of Raymond Arches, which form only at ice divides that are frozen at the bed, allows inferences of the maximum geothermal flux at two coastal domes along the Siple Coast: Engelhardt Ridge, 85 +/- 11 mW/m(2) and Shabtaie Ridge, 75 +/- 10 mW/m(2). These measurements indicate heat flows similar to measurements at Siple Dome and the Whillans grounding zone and to the continental crust average. The high values measured at Subglacial Lake Whillans and estimated from satellite observations of Curie depths are not widespread.