文章基本信息

标题：Continuous borehole optical televiewing reveals variable englacial debris concentrations at Khumbu Glacier, Nepal
本地全文：下载
作者：Katie E. Miles ; Bryn Hubbard ; Evan S. Miles 等
期刊名称：Communications Earth & Environment
电子版ISSN：2662-4435
出版年度：2021
卷号：2
期号：1
页码：1-9
DOI：10.1038/s43247-020-00070-x
语种：English
出版社：Nature Research
摘要：Surface melting of High Mountain Asian debris-covered glaciers shapes the seasonal water supply to millions of people. This melt is strongly influenced by the spatially variable thickness of the supraglacial debris layer, which is itself partially controlled by englacial debris concentration and melt-out. Here, we present measurements of deep englacial debris concentrations from debris-covered Khumbu Glacier, Nepal, based on four borehole optical televiewer logs, each up to 150 m long. The mean borehole englacial debris content is 0.7% by volume in the glacier's mid-to-upper ablation area, and increases to 6.4% by volume near the terminus. These concentrations are higher than those reported for other valley glaciers, although those measurements relate to discrete samples while our approach yields a continuous depth profile. The vertical distribution of englacial debris increases with depth, but is also highly variable, which will complicate predictions of future rates of surface melt and debris exhumation at such glaciers. High vertical variation in englacial debris concentration is found in four 150 m-deep borehole optical televiewer logs in Khumbu Glacier, Nepal, with vertically averaged englacial debris concentrations of up to 6.4% by volume towards the terminus.