Cauldron subsidence and subglacial floods
Ice cauldrons are depressions which form at the surface of ice sheets when an underlying subglacial lake empties. Notable examples of such cauldrons occur on the surface of the Vatnajökull ice cap in Iceland, and in particular are formed when subglacial volcanic eruptions occur. More generally, caul...
Main Authors: | , |
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Format: | Text |
Language: | English |
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2006
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.190.5367 http://www.maths.ox.ac.uk/%7Efowler/papers/2007.2.pdf |
Summary: | Ice cauldrons are depressions which form at the surface of ice sheets when an underlying subglacial lake empties. Notable examples of such cauldrons occur on the surface of the Vatnajökull ice cap in Iceland, and in particular are formed when subglacial volcanic eruptions occur. More generally, cauldrons will form when a subglacial lake empties during a jökulhlaup. The rate of subsidence of the ice surface is related to the rate at which the subglacial water empties from the lake. We use a viscous version of classical beam theory applied to the ice sheet to determine the relation between the subsidence rate and flood discharge, and we use the results to make inferences concerning ring fracture spacings in cauldrons, the consequent effect on flood discharge dynamics, and the likely nature of subsidence events in the Antarctic Ice Sheet. |
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