DOI: 10.1002/2017JF004505
Scopus记录号: 2-s2.0-85046133106
论文题名: Bedrock Fracture Characteristics as a Possible Control on the Distribution of Surge-Type Glaciers
作者: Crompton J.W. ; Flowers G.E. ; Stead D.
刊名: Journal of Geophysical Research: Earth Surface
ISSN: 21699003
出版年: 2018
卷: 123, 期: 5 起始页码: 853
结束页码: 873
语种: 英语
英文关键词: basal processes
; bedrock fracture
; discontinuity properties
; glacier dynamics
; glacier surges
; St. Elias Mountains
Scopus关键词: basal flow
; bedrock
; fracture mechanics
; glacier dynamics
; glacier surge
; Saint Elias Mountains
英文摘要: Glacier surging has been studied extensively and is understood as a dynamic instability at the glacier bed. Yet an explanation for the heterogeneous distribution of surge-type glaciers at the scale of a mountain range remains elusive. Here we investigate bedrock discontinuity properties in the basins of 16 surge-type and nonsurge-type glaciers in the St. Elias Mountains of Yukon, Canada. Using scaled photographs of bedrock outcrops at the margins of each glacier, we digitize traces of the bedrock discontinuities and with automated purpose-built software, quantify discontinuity properties that are a function of length, orientation, and spacing of bedrock fractures. We obtain an unexpected result: outcrops in the basins of surge-type glaciers are less fractured than those in the basins of nonsurge-type glaciers. We hypothesize that the degree of bedrock fracture may control the extent and location of a clast-rich till transition zone at the glacier bed. This zone would provide flow resistance conducive to the development of an ice reservoir and thus to surging behavior. To reconcile our observations with the global distribution of surge-type glaciers, we speculate that surge-type glaciers may occur in geological settings characterized by an intermediate range of bedrock fracture. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114011
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth Sciences, Simon Fraser University, Burnaby, BC, Canada
Recommended Citation:
Crompton J.W.,Flowers G.E.,Stead D.. Bedrock Fracture Characteristics as a Possible Control on the Distribution of Surge-Type Glaciers[J]. Journal of Geophysical Research: Earth Surface,2018-01-01,123(5)