Paleofluvial and subglacial channel networks beneath Humboldt Glacier, Greenland
Paleofluvial and subglacial channel networks beneath Humboldt Glacier, Greenland
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DOI：
10.1130/g38860.1
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发表时间：
2017-06-01
期刊：
影响因子：
5.8
通讯作者：
Kingslake, Jonathan
中科院分区：
文献类型：
--
作者：
Livingstone, Stephen J.;Chu, Winnie;Kingslake, Jonathan
冰下排水系统的识别可以为我们了解过去和现在的水文过程，景观演变和冰动力学提供信息。在这里，我们提出的证据，从卫星图像，数字高程模型，和无线电回波探测数据的一系列渠道化网络对比古河流和冰下的起源下洪堡冰川，格陵兰岛北方。洪堡北方部分下方的一个> 250公里长的树枝状古河道网络被解释为冰前特征。洪堡南部下方大致呈线性的通道，其分布与前冰盖床上发现的隧道山谷相似，很可能是被冰下融水沿着沿着冰盖床侵蚀的。我们认为，基底融水正在积极路由下古河流和冰下形成的通道网络的海岸。冰前水道网络的继承可能影响了洪堡冰川现今的位置和动态，并增强了冰川末端的选择性侵蚀。
The identification of subglacial drainage systems can inform our understanding of past and present hydrological processes, landscape evolution, and ice dynamics. Here, we present evidence from satellite imagery, digital elevation models, and radio-echo sounding data for a series of channelized networks with contrasting paleofluvial and subglacial origins beneath Humboldt Glacier, northern Greenland. A > 250-km-long, dendritic paleofluvial channel network beneath the northern portion of Humboldt is interpreted as a preglacial feature. Roughly linear channels beneath the southern portion of Humboldt, which display a similar distribution to tunnel valleys found on the beds of former ice sheets, are likely to have been eroded by subglacial meltwater routed along the ice-sheet bed. We suggest that basal meltwater is actively being routed down both the paleofluvial and subglacially formed channel networks to the coast. Inheritance of the preglacial channel network may have influenced the present-day location and dynamics of Humboldt Glacier and enhanced selective erosion at its down-glacier end.