DOI: 10.1029/2017JF004341
Scopus记录号: 2-s2.0-85052470718
论文题名: Crevasses as Indicators of Surge Dynamics in the Bering Bagley Glacier System, Alaska: Numerical Experiments and Comparison to Image Data Analysis
作者: Trantow T. ; Herzfeld U.C.
刊名: Journal of Geophysical Research: Earth Surface
ISSN: 21699003
出版年: 2018
卷: 123, 期: 8 起始页码: 1615
结束页码: 1637
语种: 英语
英文关键词: geostatistics
; glacier dynamics
; ice flow
; surge
英文摘要: One of the largest sources of uncertainty in sea level rise prediction is glacial acceleration, of which the surge phenomenon is the least understood type. The surge of the Bering Bagley Glacier System (BBGS), Alaska, in 2011–2013 has provided a rare opportunity to study the surge phenomenon in a large and complex glacier system. A surge results in widespread crevassing throughout the glacier system complicating many traditional techniques used to study glacier dynamics. In this paper, we utilize crevassing as a means to investigate the recent BBGS surge through numerical modeling and geostatistical data analysis. Following the principles of structural glaciology, image-based crevasse characterizations are obtained through geostatistical methods applied to Landsat-7 data, supplemented by airborne field observations. On the modeling side, a 3-D full-Stokes finite element model of the BBGS is developed and applied to investigate ice dynamics and surface structures during the recent surge. A von Mises criterion is adopted to simulate crevassing at the glacier surface, oriented along the axes of maximum principal tensile stress. To facilitate evaluation of model- and data-derived crevasse characteristics, three different comparison methods are introduced. General agreement in the model-data comparisons indicates that the model has the ability to represent the BBGS system during peak acceleration. The crevasse-based approach is also employed to optimize the basal sliding parameter and the von Mises stress threshold in the model. Results further indicate that bed topography is an important constraint in modeling the surge process. ©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/113293
Appears in Collections: 气候减缓与适应
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作者单位: Department of Electrical, Computer and Energy Engineering, University of Colorado, Boulder, CO, United States; Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States
Recommended Citation:
Trantow T.,Herzfeld U.C.. Crevasses as Indicators of Surge Dynamics in the Bering Bagley Glacier System, Alaska: Numerical Experiments and Comparison to Image Data Analysis[J]. Journal of Geophysical Research: Earth Surface,2018-01-01,123(8)