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Reversal of ice motion during the outburst of a glacier-dammed lake on Gornergletscher, Switzerland
Title: | Reversal of ice motion during the outburst of a glacier-dammed lake on Gornergletscher, Switzerland |
Authors: | Sugiyama, Shin Browse this author →KAKEN DB | Bauder, Andreas Browse this author | Weiss, Patrik Browse this author | Funk, Martin Browse this author |
Issue Date: | Mar-2007 |
Publisher: | International Glaciological Society |
Journal Title: | Journal of Glaciology |
Volume: | 53 |
Issue: | 181 |
Start Page: | 172 |
End Page: | 180 |
Publisher DOI: | 10.3189/172756507782202847 |
Abstract: | During the outburst flood of a glacier-dammed lake on Gornergletscher, Switzerland, in July 2004, the drained lake water triggered anomalous glacier motion. At the onset of the outburst, the ice-flow direction in the vicinity of the lake became closer to the central flowline. When the lake discharge magnitude decreased, the flow direction altered such that the ice moved back to the azimuth of the initial motion. At one of the survey points, where the ice flows parallel to the central flowline, the ice accelerated along the pre-event flow direction followed by a 180° backward motion that lasted over 2 days. These observations indicate the impact of the lake outburst on the subglacial and englacial stress conditions; however, the reversal in the flow direction is difficult to explain by drawing on our current understanding of glacier mechanics. The timing and the timescale of the flow-direction changes suggest that the elastic glacier motion and its rebound played a role under the rapidly changing stress conditions, but the Young’s modulus of ice is too large to cause the observed ice motion. Other processes, including basal separation and subglacial sediment deformation, are discussed as possible mechanisms for the reversal of the ice motion. |
Rights: | © 2007 International Glaciological Society |
Relation: | http://www.igsoc.org/ |
Type: | article |
URI: | http://hdl.handle.net/2115/34783 |
Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 杉山 慎
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