DOI: 10.5194/tc-10-2075-2016
Scopus记录号: 2-s2.0-84988378183
论文题名: Heterogeneous glacier thinning patterns over the last 40 years in Langtang Himal, Nepal
作者: Ragettli S ; , Bolch T ; , Pellicciotti F
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 5 起始页码: 2075
结束页码: 2097
语种: 英语
英文关键词: avalanche
; catchment
; digital elevation model
; earthquake event
; glacier
; satellite data
; satellite imagery
; thinning
; uncertainty analysis
; Bagmati
; Langtang Valley
; Nepal
英文摘要: This study presents volume and mass changes of seven (five partially debris-covered, two debris-free) glaciers in the upper Langtang catchment in Nepal. We use a digital elevation model (DEM) from 1974 stereo Hexagon satellite data and seven DEMs derived from 2006–2015 stereo or tri-stereo satellite imagery (e.g., SPOT6/7). The availability of multiple independent DEM differences allows the identification of a robust signal and narrowing down of the uncertainty about recent volume changes. The volume changes calculated over several multiyear periods between 2006 and 2015 consistently indicate that glacier thinning has accelerated with respect to the period 1974–2006. We calculate an ensemble-mean elevation change rate of –0.45ĝ€#x000B1;ĝ€0.18ĝ€mĝ€a−1 for 2006–2015, while for the period 1974–2006 we compute a rate of −0.24ĝ€±ĝ€0.08ĝ€mĝ€a−1. However, the behavior of glaciers in the study area is heterogeneous, and the presence or absence of debris does not seem to be a good predictor for mass balance trends. Debris-covered tongues have nonlinear thinning profiles, and we show that recent accelerations in thinning correlate with the presence of supraglacial cliffs and lakes. At stagnating glacier areas near the glacier front, however, thinning rates decreased with time or remained constant. The April 2015 Nepal earthquake triggered large avalanches in the study catchment. Analysis of two post-earthquake DEMs revealed that the avalanche deposit volumes remaining 6 months after the earthquake are negligible in comparison to 2006–2015 elevation changes. However, the deposits compensate about 40ĝ€% the mass loss of debris-covered tongues of 1 average year. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75080
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 Environmental Engineering, ETH Zürich, Zurich, Switzerland; University of Zurich, Department of Geography, Zurich, Switzerland; Institute for Cartography, Technische Universität Dresden, Dresden, Germany; Northumbria University, Department of Geography, Newcastle upon Tyne, United Kingdom
Recommended Citation:
Ragettli S,, Bolch T,, Pellicciotti F. Heterogeneous glacier thinning patterns over the last 40 years in Langtang Himal, Nepal[J]. Cryosphere,2016-01-01,10(5)