Supraglacial lake
A supraglacial lake is a body of water on the surface of the glacier . It forms in depressions on the ice surface through the accumulation of melt water .
General
Supraglacial lakes occur almost everywhere in the world, except in the polar regions, especially Antarctica , since the air temperatures near the surface are constantly in the strongly negative range and therefore do not allow liquid water. The lakes are usually below the equilibrium line (Engl. Equilibrium Line Altitude , PA), as snow or Firn absorb the melting water.
Research focus
The research projects focus on regions such as Svalbard or Greenland . The impact of an emptying lake on the ice drift is examined. The idea is that flowing water that has reached the bottom of the glacier gives the ice hydraulic buoyancy. This results in an acceleration of the ice drift, which in turn can increase the glacier calving. Especially when it comes to freshwater ice, this means a rise in sea level. Special attention is paid to the rapidly emptying supraglacial lakes, which empty almost completely in a very short time. Das et al. (2008) observed a 5.6 km² lake in 2006 that disappeared within 1.4 hours.
bibliography
- Pfiffner, A. et al. (2012): Erdwissenschaften , o. O., Haupt. ISBN 978-3-8252-3632-8 .
- Das, S. et al. (2008): Fracture Propagation to the Base of the Greenland Ice Sheet During Supraglacial Lake Drainage, in: Science , 320: 778-781.
- Selmes, N. et al. (2013): Fast Draining lakes in the Greenland Ice Sheet, in: Geophysical Research Letters , Vol. 38, L15501: 1-5.