Reconstruction of the West Antarctic Ice Sheet in Pine Island Bay during the last glacial maximum and its subsequent retreat history
Reconstruction of the West Antarctic Ice Sheet in Pine Island Bay during the last glacial maximum and its subsequent retreat history
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DOI：
10.1016/s0277-3791(02)00006-9
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发表时间：
2002-09-01
影响因子：
4
通讯作者：
Anderson, JB
中科院分区：
文献类型：
--
作者：
Lowe, AL;Anderson, JB
通过对南极松岛湾西南极冰盖晚第四纪冰期的海洋地质和地球物理研究，确定了该冰盖的冰期历史。该数据集包括多波束条带测深法和深拖侧扫声纳勘测形式的海底图像。通过中等分辨率地震数据和啁啾（3.5千赫）海底下剖面图，可以揭示沉积矿床的分布和基底表面状况。沉积物进行了采样与活塞芯，石灰质材料使用AMS放射性碳技术。研究结果表明，在过去的某个时候，冰盖在其最大范围内被固定在外大陆架上。厚厚的冰，缓慢流动，并停留在结晶基岩，受到了大量的冰下融水的内大陆架。冰层更薄，但流动更快，这是冰盖向海延伸的特征，冰盖是建立在沉积基底上的。冰消作用发生在两个阶段，在最后一次盛冰期之后不久开始。冰盖的最外延伸部分逐渐后退，停在中间大陆架的水深高度上，与16,000 C-14年前相似。在大约16，000到12，000 C-14年前，冰盖退缩恢复，并可能迅速达到今天的位置，大约10，000 C-14年前。(C)2002爱思唯尔科技有限公司版权所有。
Marine-geological and -geophysical studies were conducted to determine the Late Quaternary glacial history of the West Antarctic Ice Sheet in Pine Island Bay, Antarctica. The data set includes sea-floor imagery in the form of multibeam swath bathymetry and deep-tow side-scan sonar surveys. Distribution of sedimentary deposits and basal surface conditions are revealed through intermediate-resolution seismic data and chirp (3.5 kHz) sub-bottom profiles. Sedimentary deposits were sampled with piston cores, and calcareous material was dated using AMS radiocarbon techniques. Results from the study indicate the ice sheet was grounded on the outer shelf during its maximum extent sometime in the past. Thick ice, flowing slowly and resting on crystalline bedrock, was influenced by significant amounts of subglacial meltwater on the inner shelf. Thinner, but more rapidly flowing, ice characterized the seaward extent of the ice sheet, which was grounded on a sedimentary substrate. Deglaciation occurred in two phases, beginning soon after the last glacial maximum. The outer-most extension of the ice sheet retreated gradually, pausing on a bathymetric high on the middle shelf by similar to 16,000 C-14 years ago. Between similar to 16,000 and 12,000 C-14 years ago, ice-sheet retreat resumed, and may have proceeded rapidly to reach a present-day position by similar to 10,000 C-14 years ago. (C) 2002 Elsevier Science Ltd. All rights reserved.