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Glacier surge propagation by thermal evolution at the bed

Murray, Tavi; Stuart, Graham W.; Miller, Paul J.; Woodward, John; Smith, Andrew M.; Porter, Philip R.; Jiskoot, Hester. 2000 Glacier surge propagation by thermal evolution at the bed. Journal of Geophysical Research, 105 (B6). 13491-13507. 10.1029/2000JB900066

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Abstract/Summary

Bakaninbreen, southern Svalbard, began a prolonged surge during 1985. In 1986, an internal reflecting horizon on radio echo sounding data was interpreted to show that the position of the surge front coincided with a transition between areas of warm (unfrozen) and cold (frozen) bed. Ground-penetrating radar lines run in 1996 and 1998 during early quiescence show that the basal region of the glacier is characterized by a strong reflection, interpreted as the top of a thick layer of sediment-rich basal ice. Down glacier of the present surge front, features imaged beneath the basal reflection are interpreted as the bottom of the basal ice layer, the base of a permafrost layer, and local ice lenses. This indicates that this region of the bed is cold. Up glacier of the surge front, a scattering zone above the basal reflection is interpreted as warm ice. There is no evidence for this warm zone down glacier of the surge front, nor do we see basal permafrost up glacier of it. Thus, as in early surge phase, the location of the surge front is now at the transition between warm and cold ice at the glacier bed. We suggest that the propagation of the front is associated with this basal thermal transition throughout the surge. Because propagation of the front occurs rapidly and generates only limited heat, basal motion during fast flow must have been restricted to a thin layer at the bed and occurred by sliding or deformation localized at the ice-bed interface.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1029/2000JB900066
Programmes: BAS Programmes > Pre 2000 programme
ISSN: 0148-0227
Additional Information. Not used in RCUK Gateway to Research.: Not subject to U.S. copyright. Published 2012 American Geophysical Union. Further reproduction or electronic distribution is not permitted.
Date made live: 14 Jan 2013 12:18 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/21094

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