Quantification of Everest region glacier velocities between 1992 and 2002, using satellite radar interferometry and feature tracking
Quantification of Everest region glacier velocities between 1992 and 2002, using satellite radar interferometry and feature tracking
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DOI：
10.3189/002214309789470987
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发表时间：
2009
影响因子：
3.4
通讯作者：
D. Quincey;A. Luckman;D. Benn
中科院分区：
文献类型：
--
作者：
D. Quincey;A. Luckman;D. Benn
摘要 众所周知，喜马拉雅山的许多冰川口是停滞的，并且表面梯度较低，这些条件有利于形成由终端冰碛或残余冰川口蓄积的冰川湖。在这项研究中，我们使用干涉测量和特征跟踪技术来量化珠穆朗玛峰（珠穆朗玛峰；萨加玛塔）地区 20 条冰川的停滞程度，随后我们研究了当地流域地形与冰动态之间的关系。结果表明，只有一个所研究的冰川——Kangshung 冰川在其整个表面上是动态的，在高海拔地区记录到的流速大于 40 m a−1。其他十二条冰川也显示出一些流动的证据，但一般都具有长而停滞的舌状特征，表明广泛的衰退和原位腐烂。其余七个冰川在任何可用数据集中都没有显示出流动的证据。海拔测量数据表明，流域地形在控制冰川流动状况方面发挥着重要作用，那些由宽阔的高海拔堆积区供给的冰川显示出最广泛的活动冰，而那些起源于低海拔的冰川则显示出大面积的停滞冰。从 SRTM 数字高程模型提取的表面轮廓表明，停滞的鼻子的特征是非常低（<2°）的表面角度，并且向下消耗是研究区域普遍的消融模式。
Abstract Many glacier snouts in the Himalaya are known to be stagnant and exhibiting low surface gradients, conditions that are conducive to the formation of glacial lakes impounded either by the terminal moraine or by the remnant glacier snout. In this study, we use interferometry and feature-tracking techniques to quantify the extent of stagnation in 20 glaciers across the Everest (Qomolangma; Sagarmatha) region, and subsequently we examine the relationship between local catchment topography and ice dynamics. The results show that only one of the studied glaciers, Kangshung Glacier, is dynamic across its entire surface, with flow rates greater than 40 m a−1 being recorded in high-elevation areas. Twelve other glaciers show some evidence of flow, but are generally characterized by long, stagnant tongues, indicating widespread recession and in situ decay. The remaining seven glaciers show no evidence of flow in any of the available datasets. Hypsometric data suggest that catchment topography plays an important role in controlling glacier flow regimes, with those fed by wide, high-altitude accumulation areas showing the most extensive active ice, and those originating at low elevations exhibiting large areas of stagnant ice. Surface profiles extracted from a SRTM digital elevation model indicate that stagnant snouts are characterized by very low (<2°) surface angles and that down-wasting is the prevalent ablation pattern in the study area.