Subglacial lakes are large pockets of water that lie beneath large ice sheets. Despite mean annual ice surface temperatures of below −50°C, background levels of geothermal heating (∼50 mW m−2) ensure that, where the ice is in excess of 3 km thick, basal temperatures can reach the pressure melting point. Subglacial water flows under the influence of gravity and ice overburden pressure. It can flow “uphill” if the magnitude of the ice surface slope is greater than 1/10th of the bedrock slope. Water collects, however, where basal slopes are larger, to form subglacial lakes.
|Title of host publication
|Encyclopedia of Lakes and Reservoirs
|Lars Bengtsson, Reginald W. Herschy, Rhodes W. Fairbridge
|Place of Publication
|Number of pages
|Published - 2012
|Encyclopedia of Earth Sciences Series