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Short-term variations in glacier flow controlled by subglacial water pressure at Lauteraargletscher, Bernese Alps, Switzerland
| Title: | Short-term variations in glacier flow controlled by subglacial water pressure at Lauteraargletscher, Bernese Alps, Switzerland |
| Authors: | Sugiyama, Shin Browse this author →KAKEN DB | | Gudmundsson, G. Hilmar Browse this author |
| Issue Date: | Jun-2004 |
| Publisher: | International Glaciological Society |
| Journal Title: | Journal of Glaciology |
| Volume: | 50 |
| Issue: | 170 |
| Start Page: | 353 |
| End Page: | 362 |
| Publisher DOI: | 10.3189/172756504781829846 |
| Abstract: | Short-term variations in horizontal and vertical surface motion were studied with high temporal resolution during the ablation season in Lauteraargletscher, Bernese Alps, Switzerland. Horizontal surface flow speed oscillated diurnally, showing a correlation with the water level in a borehole. Flow speed increased as a function of the water level, with an asymptote at the ice overburden level. This observation implied that the flow variations were principally controlled by the local water pressure which enhanced basal motions. Detailed examination of the diurnal variations, however, showed that the speed was larger when the pressure was increasing than when it was decreasing. Greater speed with increasing pressure was interpreted by subglacial watercavity opening and/or longitudinal stress coupling with the upper reaches of the glacier. Upward surface movements were observed when the glacier flow speed increased. Simultaneous measurement of internal vertical strain in a borehole showed that the uplift had two different sources: vertical straining of ice and volume increase of subglacialwater cavities. The vertical surface movement was largely affected by the vertical strain, and the uplift events could not be simply attributed to cavity opening. |
| Rights: | © 2004 International Glaciological Society |
| Relation: | http://www.igsoc.org/ |
| Type: | article |
| URI: | http://hdl.handle.net/2115/34782 |
| 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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