...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Relating bed character and subglacial morphology using seismic data from Thwaites Glacier, West Antarctica
【24h】

Relating bed character and subglacial morphology using seismic data from Thwaites Glacier, West Antarctica

机译：在西南极洲塔克斯冰川的地震数据相关床特征和沉淀形态

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Seismic measurements on Thwaites Glacier show a spatially variable bed character, with implications for ice-sheet stability. The West Antarctic Ice Sheet is losing mass rapidly through outlet glaciers and ice streams in the Amundsen Sea Embayment, including Thwaites Glacier, where limited observations and modeling suggest that ice-flow rates depend on bed properties. Here we characterize bed properties of Thwaites Glacier based on amplitude analysis of reflection-seismic data from a similar to 40-km-long profile collected in the approximate flow direction and two similar to 10-km-long profiles transverse to flow. The upstream portion of the seismic profile reveals a similar to 12-km long sedimentary basin with ice-flow-aligned bedforms capped by a continuous till layer that is likely soft and deforming (porosity similar to 0.4-0.45), with several locations where water has pooled at the bed. Downstream of the sedimentary basin, the bed rises by similar to 400 m over similar to 25 km into subglacial highlands. Our seismic survey of these subglacial highlands reveals strong spatial variations in bed character across rugged topography (similar to 200 m amplitude at similar to 2- to 5-km wavelength) resembling crag-and-tails. Till on the stoss sides (facing upglacier) of topographic highs is more consolidated (porosity similar to 0.3-0.35 or lower), whereas the lee sides (facing downglacier) and flat regions exhibit porosity similar to the till of the upstream sedimentary basin. Modeling studies could use the observed correlation between bed character and bed aspect and slope to extend our observations to other parts of Thwaites Glacier, resulting in more-realistic models of future grounding-line retreat. Our findings highlight the need for more geophysical constraints on bed properties for important outlets in Antarctica and Greenland. (C) 2018 Published by Elsevier B.V.
机译：冰川上的地震测量显示空间可变的床特征，具有对冰板稳定性的影响。西南南极冰盖通过阿蒙森海扶盟的出口冰川和冰流迅速减肥，包括冰川，其中有限的观察和建模表明冰流量取决于床特性。在这里，我们基于从近似流动方向上收集的类似于40公里长的型材的反射地震数据的幅度分析，其特征在于，基于近似流动方向上的40千米长的型材，两个类似于横向流动的10千米长的型材的幅度分析。地震型材的上游部分揭示了类似于12公里长的沉积盆，具有冰流量对齐的玻璃形式，该弯曲的床形式由连续的达到柔软和变形（孔隙率类似于0.4-0.45），其中几个地方已在床上汇集。下游沉积盆地，床上升高到400米以上，与25公里进入底层高地。我们对这些底层高地的地震调查揭示了崎岖地形的床特性的强烈空间变化（类似于200米的幅度，类似于2至5公里的波长），类似于裂缝和尾部。在地形高度的鞋形侧面（面向上升的侧面）更加巩固（孔隙率类似于0.3-0.35或更低），而李侧（下唇）和平坦区域表现出类似于上游沉积盆地的孔隙率。建模研究可以使用床特征和床方面之间观察到的相关性，并将观察扩展到Thwaites冰川的其他部分，从而导致未来的接地线撤退的更现实的模型。我们的调查结果强调了对南极洲和格陵兰岛重要网点的床铺物业的需要更多地地球物理限制。 （c）2018由elestvier b.v出版。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号