DOI: 10.1029/2017JF004358
Scopus记录号: 2-s2.0-85047633786
论文题名: Tidewater Glacier Surges Initiated at the Terminus
作者: Sevestre H. ; Benn D.I. ; Luckman A. ; Nuth C. ; Kohler J. ; Lindbäck K. ; Pettersson R.
刊名: Journal of Geophysical Research: Earth Surface
ISSN: 21699003
出版年: 2018
卷: 123, 期: 5 起始页码: 1035
结束页码: 1051
语种: 英语
英文关键词: dynamics
; glaciers
; remote sensing
; surges
; Svalbard
; tidewater
Scopus关键词: enthalpy
; glacier surge
; meltwater
; rainwater
; remote sensing
; thermodynamics
; tidewater glacier
; Aavatsmarkbreen
; Arctic
; Spitsbergen
; Svalbard
; Svalbard and Jan Mayen
英文摘要: There have been numerous reports that surges of tidewater glaciers in Svalbard were initiated at the terminus and propagated up-glacier, in contrast with downglacier-propagating surges of land-terminating glaciers. Most of these surges were poorly documented, and the cause of this behavior was unknown. We present detailed data on the recent surges of two tidewater glaciers, Aavatsmarkbreen and Wahlenbergbreen, in Svalbard. High-resolution time series of glacier velocities and evolution of crevasse patterns show that both surges propagated up-glacier in abrupt steps. Prior to the surges, both glaciers underwent retreat and steepening, and in the case of Aavatsmarkbreen, we demonstrate that this was accompanied by a large increase in driving stress in the terminal zone. The surges developed in response to two distinct processes. (1) During the late quiescent phase, internal thermodynamic processes and/or retreat from a pinning point caused acceleration of the glacier front, leading to the development of terminal crevasse fields. (2) Crevasses allowed surface meltwater and rainwater to access the bed, causing flow acceleration and development of new crevasses up-glacier. Upward migration of the surge coincided with stepwise expansion of the crevasse field. Geometric changes near the terminus of these glaciers appear to have led to greater strain heating, water production, and storage at the glacier bed. Water routing via crevasses likely plays an important role in the evolution of surges. The distinction between internally triggered surges and externally triggered speedups may not be straightforward. The behavior of these glaciers can be understood in terms of the enthalpy cycle model. ©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/113950
Appears in Collections: 气候减缓与适应
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作者单位: School of Geography and Sustainable Development, University of St Andrews, Saint Andrews, United Kingdom; Department of Geography, College of Science, Swansea University, Swansea, United Kingdom; Department of Arctic Geophysics, The University Centre in Svalbard, Longyearbyen, Norway; Department of Geosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway; Norwegian Polar Institute, Tromsø, Norway; Department of Earth Sciences, Uppsala University, Uppsala, Sweden
Recommended Citation:
Sevestre H.,Benn D.I.,Luckman A.,et al. Tidewater Glacier Surges Initiated at the Terminus[J]. Journal of Geophysical Research: Earth Surface,2018-01-01,123(5)