| DOI: | 10.1002/2016GL068337
|
| 论文题名: | Subseasonal changes observed in subglacial channel pressure, size, and sediment transport |
| 作者: | Gimbert F.; Tsai V.C.; Amundson J.M.; Bartholomaus T.C.; Walter J.I.
|
| 刊名: | Geophysical Research Letters
|
| ISSN: | 0094-9108
|
| EISSN: | 1944-8839
|
| 出版年: | 2016
|
| 卷: | 43, 期:8 | | 起始页码: | 3786
|
| 结束页码: | 3794
|
| 语种: | 英语
|
| 英文关键词: | glacier sliding
; sediment transport
; seismic noise
; subglacial hydrology
; water pressure
|
| Scopus关键词: | Erosion
; Flow of water
; Pressure gradient
; Sediment transport
; Sediments
; Seismology
; Continuous measurements
; Glacier surface velocity
; High water pressure
; Seismic ground motions
; Seismic noise
; Seismic observation
; Subglacial hydrology
; Water pressures
; Sedimentation
; channel change
; erosion rate
; glacial hydrology
; glacier dynamics
; ground motion
; ice flow
; ice sheet
; pressure gradient
; seasonal variation
; sediment transport
; seismic noise
; sliding
; subglacial environment
; Alaska
; Mendenhall Glacier
; United States
|
| 英文摘要: | Water that pressurizes the base of glaciers and ice sheets enhances glacier velocities and modulates glacial erosion. Predicting ice flow and erosion therefore requires knowledge of subglacial channel evolution, which remains observationally limited. Here we demonstrate that detailed analysis of seismic ground motion caused by subglacial water flow at Mendenhall Glacier (Alaska) allows for continuous measurement of daily to subseasonal changes in basal water pressure gradient, channel size, and sediment transport. We observe intermittent subglacial water pressure gradient changes during the melt season, at odds with common assumptions of slowly varying, low-pressure channels. These observations indicate that changes in channel size do not keep pace with changes in discharge. This behavior strongly affects glacier dynamics and subglacial channel erosion at Mendenhall Glacier, where episodic periods of high water pressure gradients enhance glacier surface velocity and channel sediment transport by up to 30% and 50%, respectively. We expect the application of this framework to future seismic observations acquired at glaciers worldwide to improve our understanding of subglacial processes. ©2016. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84992294271&doi=10.1002%2f2016GL068337&partnerID=40&md5=2c14adccd46797e2ed455d2364cfa05a
|
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/10071
|
| Appears in Collections: | 科学计划与规划
气候变化与战略
|
|
There are no files associated with this item.
|
|
作者单位: | Seismological Laboratory, California Institute of Technology, Pasadena, CA, United States
|
| Recommended Citation: | |
Gimbert F.,Tsai V.C.,Amundson J.M.,et al. Subseasonal changes observed in subglacial channel pressure, size, and sediment transport[J]. Geophysical Research Letters,2016-01-01,43(8).
|
|
|