EAS100 Lecture Notes - Lecture 21: Antarctica, Cirque Glacier, Glacier Mass Balance

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Jeffrey Kavanaugh

Document Summary

Antartica has ~300 subglacier lakes as a result of geo-thermal heating. Water at the surface - not a result of surface melting - high pressures raise the ground water all the way up so the glacier "floats" Water reaches the bed through several methods - cravasses, geo-thermal melting and upstream melt sources. Pressure from subglacier water has an angled normal force which "pushes" the glacier down-slope. With high pressure from glacier + sediments, the sediments break down and also cause increased rate of movement. Conditions of the glacier bed predomadate the characteristics of flow. Water pressure changes can find "subglacier river systems" daily fluctuations during the summer season (high at night, low in day) increases gradually from low after summer, high by next summer. Less sediment deformation when water pressures are high (glacier. More sediment deformation when water pressure is low (glacier "drags") Annual snow line marks boundry of areas that have snow year-