Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data: New results
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data: New results
复制标题
使用空气重力和原位地球物理数据建模的松岛冰川冰架下的冰下测深和沉积物分布：新结果
DOI：
10.1016/j.epsl.2015.10.037
复制
发表时间：
2016
影响因子：
5.3
通讯作者：
Riverman
中科院分区：
文献类型：
--
作者：
Peters;Sasgen;Anandakrishnan;Riverman
西南极冰盖（WAIS）阿蒙森海部分的松岛冰川（PIG）正在失去质量，并导致全球海平面加速上升。虽然最近的观测和建模已经确定了相对温暖的北极圈深水（CDW）下的PIG冰架（PIGIS）的主要驱动力的入侵，这种冰量损失，缺乏精确的测深限制进一步了解冰-海洋相互作用，提高建模的准确性。在这里，我们提出了最新的水深和沉积物分布PIGIS下，建模的约束条件下，从主动源地震数据，观测自主水下航行器，和区域重力异常场来自卫星重力观测的航空重力数据反演。模拟水深测量显示，在PIGIS中部下方有一个海脊，高出周围海床350至400米，海脊上方最小水柱厚度为200米，海脊贯穿整个45公里宽的冰架，没有深槽穿过，证实了先前预测的冰架下海洋环流的一般特征。然而，相对较低的分辨率的空气重力数据和我们的反演方法的局限性留下了一种可能性，即有一个未被发现的，几公里宽或更窄的槽，可能会改变预测的冰架下的海洋环流。模拟的沉积物分布表明，PIG主干当前接地区附近有一个厚达10800 m的沉积盆地，并向内陆延伸，还有一个海底山脊向海的区域，该区域沉积物薄或不存在，结晶基底暴露，向海延伸至松岛湾。因此，海底洋脊标志着从厚沉积盆地过渡到一个没有或几乎没有沉积物的区域，厚沉积盆地提供了一个光滑的界面，冰可以通过滑动或沉积物变形很容易地流过，而粗糙的界面主要是通过变形流过。我们假设，后末次冰期最大撤退的PIG稳定在这个位置，因为在基础条件的空间过渡。这反过来又支持了一个假设，即最近的撤退PIG强烈被迫，可能是由于海洋环流的变化，而不是因为对冰河时代结束或PIG内陆或下方的其他变化的持续反应而发生的。
Pine Island Glacier (PIG) in the Amundsen Sea sector of the West Antarctic Ice Sheet (WAIS) is losing mass and contributing to global sea-level rise at an accelerating rate. Although recent observations and modeling have identified the incursion of relatively warm Circumpolar Deep Water (CDW) beneath the PIG ice shelf (PIGIS) as the main driver of this ice-mass loss, the lack of precise bathymetry limits furthering our understanding of the ice–ocean interactions and improving the accuracy of modeling. Here we present updated bathymetry and sediment distribution beneath the PIGIS, modeled by the inversion of aerogravity data with constraints from active-source seismic data, observations from an autonomous underwater vehicle, and the regional gravity-anomaly field derived from satellite gravity observations. Modeled bathymetry shows a submarine ridge beneath the middle of PIGIS that rises ∼350 to 400 m above the surrounding sea floor, with a minimum water-column thickness of ∼200 m above it. This submarine ridge continues across the whole width of the 45-km wide ice shelf, with no deep troughs crossing it, confirming the general features of the previously predicted sub-ice-shelf ocean circulation. However, the relatively low resolution of the aerogravity data and limitations in our inversion method leave a possibility that there is an undetected, few-kilometers-wide or narrower trough that may alter the predicted sub-ice-shelf ocean circulation. Modeled sediment distribution indicates a sedimentary basin of up to ∼800 m thick near the current grounding zone of the main PIG trunk and extending farther inland, and a region seaward of the submarine ridge where sediments are thin or absent with exposed crystalline basement that extends seaward into Pine Island Bay. Therefore, the submarine ridge marks the transition from a thick sedimentary basin providing a smooth interface over which ice could flow easily by sliding or sediment deformation, to a region with no to little sediments and instead a rough interface over which ice flows mainly by deformation. We hypothesize that the post-Last Glacial Maximum retreat of PIG stabilized at this location because of the spatial transition in basal conditions. This in turn supports the hypothesis that the recent retreat of PIG was strongly forced, probably by changes in ocean circulation, rather than occurring because of ongoing response to the end of the ice age or other changes inland of or beneath PIG.
登录
查看更多内容
影响因子：
4
作者：
Lowe, AL;Anderson, JB
通讯作者：
Anderson, JB
耕作流变学的规模独立性
影响因子：
3.4
作者：
S. Tulaczyk
通讯作者：
S. Tulaczyk
阿蒙森海湾陆架从冰期前到近代的地震地层记录：南极西部冰盖动态的证据
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
K. Gohl;G. Uenzelmann‐Neben;R. Larter;C. Hillenbrand;K. Hochmuth;T. Kalberg;Estella Weigelt;B. Davy;G. Kuhn;F. Nitsche
通讯作者：
F. Nitsche
自末次盛冰期以来，西南极洲松岛湾冰退缩的差异：来自多道地震反射数据的指示。
影响因子：
2.9
作者：
G. Uenzelmann‐Neben;K. Gohl;R. Larter;P. Schlüter
通讯作者：
P. Schlüter
使用空气重力和自主水下航行器数据建模的西南极洲松岛冰川冰架下的冰下测深和沉积层分布
影响因子：
2.9
作者：
A. Muto;S. Anandakrishnan;R. Alley
通讯作者：
R. Alley