DOI: 10.5194/tc-11-841-2017
Scopus记录号: 2-s2.0-85016509924
论文题名: Internal structure of two alpine rock glaciers investigated by quasi-3-D electrical resistivity imaging
作者: Emmert A ; , Kneisel C
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 2 起始页码: 841
结束页码: 855
语种: 英语
英文关键词: active layer
; data quality
; electrical resistivity
; landform
; meltwater
; permafrost
; rock glacier
; topography
; valley glacier
英文摘要: Interactions between different formative processes are reflected in the internal structure of rock glaciers. Therefore, the detection of subsurface conditions can help to enhance our understanding of landform development. For an assessment of subsurface conditions, we present an analysis of the spatial variability of active layer thickness, ground ice content and frost table topography for two different rock glaciers in the Eastern Swiss Alps by means of quasi-3-D electrical resistivity imaging (ERI). This approach enables an extensive mapping of subsurface structures and a spatial overlay between site-specific surface and subsurface characteristics. At Nair rock glacier, we discovered a gradual descent of the frost table in a downslope direction and a constant decrease of ice content which follows the observed surface topography. This is attributed to ice formation by refreezing meltwater from an embedded snow bank or from a subsurface ice patch which reshapes the permafrost layer. The heterogeneous ground ice distribution at Uertsch rock glacier indicates that multiple processes on different time domains were involved in the development. Resistivity values which represent frozen conditions vary within a wide range and indicate a successive formation which includes several advances, past glacial overrides and creep processes on the rock glacier surface. In combination with the observed topography, quasi-3-D ERI enables us to delimit areas of extensive and compressive flow in close proximity. Excellent data quality was provided by a good coupling of electrodes to the ground in the pebbly material of the investigated rock glaciers. Results show the value of the quasi-3-D ERI approach but advise the application of complementary geophysical methods for interpreting the results. © 2017 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75577
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Institute of Geography and Geology, University of Würzburg, Würzburg, Germany
Recommended Citation:
Emmert A,, Kneisel C. Internal structure of two alpine rock glaciers investigated by quasi-3-D electrical resistivity imaging[J]. Cryosphere,2017-01-01,11(2)