Totten Glacier subglacial hydrology determined from geophysics and modeling
Totten Glacier subglacial hydrology determined from geophysics and modeling
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DOI：
10.1016/j.epsl.2019.115961
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发表时间：
2020-02-01
影响因子：
5.3
通讯作者：
Blankenship, D. D.
中科院分区：
文献类型：
--
作者：
Dow, C. F.;McCormack, F. S.;Blankenship, D. D.
极光冰下盆地 (ASB) 为托滕冰川提供水源，是一个位于海平面以下的海洋盆地，相当于全球海平面高度 3.5 m。该地区未来海平面上升的速度主要取决于托滕冰架的稳定性以及对接地线上游冰流动力学的控制，这两者都可能受到冰下水文的影响。我们将 GIaDS 冰下水文学模型应用于 ASB，以研究分布式高效排水系统的空间模式是否影响托滕冰川的动态。我们通过将建模的基础水压和水深结果与镜面反射内容数据进行比较，从一系列灵敏度测试中确定最合适的模型配置。这些数据来自 ICECAP 对同一地区的雷达调查，代表了基础水积累的地区。模拟的基础水文特性和镜面反射含量之间的最佳匹配表明，ASB槽中分布水的区域在水深和水压方面具有很强的对应性，但在接地线附近的水深和镜面反射含量之间的对应性较弱。这可能是由于存在几个通过接地线排入托滕冰架头部的大型通道，这些通道在镜面反射内容数据中可能不如分布式系统那样得到很好的体现。这些通道可能会对托滕冰架的融化产生重大影响，从而影响其稳定性。在ASB内，高水压和大量积水的区域与冰流较快的区域很好地对应，这表明一些控制着该区域冰动态的基础水文学。 (C) 2019 Elsevier B.V. 保留所有权利。
Aurora Subglacial Basin (ASB), which feeds Totten Glacier, is a marine basin lying below sea level and contains up to 3.5 m of global sea level equivalent. Rates of future sea level rise from this area are primarily dependent on the stability of Totten Ice Shelf and the controls on ice flow dynamics upstream of the grounding line, both of which may be influenced by subglacial hydrology. We apply the GIaDS subglacial hydrology model to ASB to examine whether the spatial patterns of distributed and efficient drainage systems impact the dynamics of Totten Glacier. We determine the most appropriate model configuration from our series of sensitivity tests by comparing the modeled basal water pressure and water depth results with specularity content data. Those data are derived from ICECAP radar surveys over the same region and represent regions of basal water accumulation. The best match between simulated basal hydrology properties and specularity content shows a strong correspondence in regions of distributed water in the ASB troughs for both water depth and water pressure, but weak correspondence between water depth and specularity content near the grounding line. This may be due to the presence of several large channels draining over the grounding line into the head of Totten Ice Shelf, which are likely not as well represented in the specularity content data as distributed systems. These channels may have a significant impact on melt, and therefore the stability, of Totten Ice Shelf. Within ASB, regions of high water pressure and greater water accumulation correspond well with regions of faster ice flow, suggesting some control a basal hydrology on ice dynamics in this region. (C) 2019 Elsevier B.V. All rights reserved.