Deep sea-floor evidence of past ice streams off the Antarctic Peninsula
Deep sea-floor evidence of past ice streams off the Antarctic Peninsula
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南极半岛过去冰流的深海底证据
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Calafat
中科院分区：
文献类型：
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作者：
M. Canals;R. Urgeles;A. Calafat
南极半岛北方外过去存在一个巨大的冰流，这是由一个向上凸起的细长沉积体提出的，现在平均水深为1000米。由于其形态特征，即，一组平行至近平行的脊、槽，长100公里，总宽25公里，我们称这种沉积体为束状构造。我们假设，束结构的形成积累的基础变形，直到其母冰流。从它的位置，大小和整体特征来看，这里描述的束状结构构成了保存最好的，最大的，最深的，相对低纬度的巨型冰流的证据，这些冰流在冰川盛期流向南极洲近海。束结构揭示了非常动态的行为在南极北方半岛在末次冰期最大，集水区排水迅速海洋为基础的关键冰下条件下的冰帽。束状构造代表了一种新的巨型流线型冰川地貌。
The past existence of a giant ice stream off the northern end of the Antarctic Peninsula is suggested by a convex-upward, elongated sediment body now at a mean water depth of 1000 m. Because of its morphological characteristics, i.e., a set of parallel to subparallel ridges and grooves to 100 km long, with an overall width of 25 km, we call this depositional body a bundle structure. We hypothesize that bundle structures form by accumulation of basal deformation till under their parent ice streams. From its location, size, and overall characteristics the bundle structure described here constitutes the best preserved, largest, deepest, and relatively low latitude evidence of giant ice streams that flowed offshore Antarctica during glacial maxima. Bundle structures reveal the very dynamic behavior of ice caps in the northern Antarctic Peninsula during the last glacial maximum, with catchment areas draining rapidly under marine-based critical subglacial conditions. Bundle structures represent a new megascale streamlined glacial landform.