New gravity-derived bathymetry for the Thwaites, Crosson and Dotson ice shelves revealing two ice shelf populations
New gravity-derived bathymetry for the Thwaites, Crosson and Dotson ice shelves revealing two ice shelf populations
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Thwaites、Crosson 和 Dotson 冰架的新重力测深揭示了两个冰架种群
DOI：
10.5194/tc-2019-294
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发表时间：
2020
影响因子：
--
通讯作者：
J. Paden
中科院分区：
文献类型：
--
作者：
T. Jordan;D. Porter;K. Tinto;R. Millan;A. Muto;K. Hogan;R. Larter;A. Graham;J. Paden
冰架通过其支撑作用在冰盖的长期稳定中发挥着关键作用。潜在的水深测量和洞穴厚度是模拟未来冰盖演变的关键输入。然而，直接观测冰架下水深是耗时、后勤风险的，而且在某些地区根本不可能实现。在这里，我们使用新的航空和海洋重力、雷达测深和带状测深的汇编，以提供快速变化的西南极Thwaites冰川外部和邻近的多特森和克罗森冰架下方的冰架下水深的新估计。这一地区特别值得关注，因为斯韦茨冰川系统地势较低的内陆逆坡使其容易受到海洋冰盖不稳定的影响，自1993年以来观察到的接地线快速后退表明这一过程可能正在进行中。我们的结果证实了一条主要的航道>；800米深延伸到Thwaites冰川前面数十公里，而邻近的冰架被更复杂的水深测量所覆盖。我们新的水深测量与冰架吃水的比较表明，自1993年以来形成的冰架由不同的群体组成，其中吃水与下伏的水深测量非常一致，不同于较旧的冰架，后者显示的冰底深度更均匀。这表明，尽管一些地区的冰架底部融化迅速，但这些最近漂浮的冰架部分还没有与它们后退的接地线位置和底层海洋系统处于动态平衡状态，这一因素必须包括在该地区未来的演化模型中。
Ice shelves play a critical role in the long-term stability of ice sheets through their buttressing effect. The underlying bathymetry and cavity thickness are key inputs for modelling future ice sheet evolution. However, direct observation of sub-ice-shelf bathymetry is time-consuming, logistically risky, and in some areas simply not possible. Here we use new compilations of airborne and marine gravity, radar depth sounding, and swath bathymetry to provide new estimates of sub-ice-shelf bathymetry outboard of the rapidly changing West Antarctic Thwaites Glacier and beneath the adjacent Dotson and Crosson ice shelves. This region is of special interest, as the low-lying inland reverse slope of the Thwaites Glacier system makes it vulnerable to marine ice sheet instability, with rapid grounding line retreat observed since 1993 suggesting this process may be underway. Our results confirm a major marine channel > 800 m deep extends tens of kilometres to the front of Thwaites Glacier, while the adjacent ice shelves are underlain by more complex bathymetry. Comparison of our new bathymetry with ice shelf draft reveals that ice shelves formed since 1993 comprise a distinct population where the draft conforms closely to the underlying bathymetry, unlike the older ice shelves, which show a more uniform depth of the ice base. This indicates that despite rapid basal melting in some areas, these recently floated parts of the ice shelf are not yet in dynamic equilibrium with their retreated grounding line positions and the underlying ocean system, a factor which must be included in future models of this region’s evolution.
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南极洲西部松岛冰川二十世纪脱底和退缩的高分辨率冰架下海底记录
DOI：
10.1002/2017jf004311
发表时间：
2017
期刊：
Earth Surface
影响因子：
--
作者：
Davies D
通讯作者：
Davies D
影响因子：
5.2
作者：
Hodgson, Dominic A.;Jordan, Tom A.;Vaughan, David G.
通讯作者：
Vaughan, David G.
影响因子：
3.4
作者：
Griggs, J. A.;Bamber, J. L.
通讯作者：
Bamber, J. L.
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
影响因子：
5.3
作者：
Peters;Sasgen;Anandakrishnan;Riverman
通讯作者：
Riverman
影响因子：
5.2
作者：
Howat, Ian M.;Porter, Claire;Morin, Paul
通讯作者：
Morin, Paul