Rock debris on glaciers: a mechanism for reducing glacier sensitivity to climate change

Rock debris covering a glacier surface affects the local melt rate by regulating the amount of solar energy available for melting. Supraglacial debris with a thickness of about 2 cm or more insulates the ice, thereby reducing the heat flux. This reduction of melt rate allows heavily debris-covered g...

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Bibliographic Details
Main Author: Herreid, Samuel
Format: Still Image
Language:unknown
Published: 2012
Subjects:
Online Access:http://hdl.handle.net/11122/1517
Description
Summary:Rock debris covering a glacier surface affects the local melt rate by regulating the amount of solar energy available for melting. Supraglacial debris with a thickness of about 2 cm or more insulates the ice, thereby reducing the heat flux. This reduction of melt rate allows heavily debris-covered glaciers to extend further down-valley than meteorological variables alone would suggest. Here we present a regional study of supraglacial debris cover in the Delta Mountains, a sub-range of the Alaska Range. Using remote sensing and in situ measurements we consider the following questions: -How does glacier and debris-covered area change from 1986 to 2010? -Can we estimate debris thickness remotely? -How does debris affect melt? -Will ice melt cease below two meters of debris? -Is there a correlation between geologic setting and debris cover?