Polyak L, Edwards M H, Coakley B J, Jakobsson M
Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA.
Nature. 2001 Mar 22;410(6827):453-7. doi: 10.1038/35068536.
It has been proposed that during Pleistocene glaciations, an ice cap of 1 kilometre or greater thickness covered the Arctic Ocean. This notion contrasts with the prevailing view that the Arctic Ocean was covered only by perennial sea ice with scattered icebergs. Detailed mapping of the ocean floor is the best means to resolve this issue. Although sea-floor imagery has been used to reconstruct the glacial history of the Antarctic shelf, little data have been collected in the Arctic Ocean because of operational constraints. The use of a geophysical mapping system during the submarine SCICEX expedition in 1999 provided the opportunity to perform such an investigation over a large portion of the Arctic Ocean. Here we analyse backscatter images and sub-bottom profiler records obtained during this expedition from depths as great as 1 kilometre. These records show multiple bedforms indicative of glacial scouring and moulding of sea floor, combined with large-scale erosion of submarine ridge crests. These distinct glaciogenic features demonstrate that immense, Antarctic-type ice shelves up to 1 kilometre thick and hundreds of kilometres long existed in the Arctic Ocean during Pleistocene glaciations.
有人提出，在更新世冰川期，北冰洋被厚度达1公里或更厚的冰盖所覆盖。这一观点与普遍认为北冰洋仅被常年海冰和零星冰山覆盖的看法形成了对比。海底详细测绘是解决这一问题的最佳方法。尽管海底图像已被用于重建南极大陆架的冰川历史，但由于操作限制，北冰洋收集的数据很少。1999年潜艇SCICEX考察期间使用地球物理测绘系统，为在北冰洋大部分区域进行此类调查提供了机会。在此，我们分析了此次考察期间从深度达1公里处获得的后向散射图像和海底剖面记录。这些记录显示出多种指示冰川对海底冲刷和塑造的底形，以及海脊顶部的大规模侵蚀。这些独特的冰川成因特征表明，在更新世冰川期，北冰洋存在着厚度达1公里、长达数百公里的巨大的南极型冰架。
