Modelling of Kealey Ice Rise, Antarctica, reveals stable ice-flow conditions in East Ellsworth Land over millennia
Modelling of Kealey Ice Rise, Antarctica, reveals stable ice-flow conditions in East Ellsworth Land over millennia
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南极洲基利冰升模型揭示了东埃尔斯沃思地数千年来稳定的冰流条件
DOI：
10.3189/2014jog13j089
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发表时间：
2014
影响因子：
3.4
通讯作者：
Edward C. King
中科院分区：
文献类型：
--
作者：
C. Martín;G. Gudmundsson;Edward C. King
冰分界处的流动、形状、大小和内部结构不仅取决于当地条件，还取决于周围冰块的流动状况和过去的历史。在这里，我们使用来自南极洲西部埃尔斯沃思地Kealey冰隆起的现场数据，结合流动模型来研究周围冰块流动中任何可能的瞬变迹象。在卫星图像中，凯利冰脊显示出与冰脊平行的线性表面特征，在探地雷达数据中，它有一个明显的分层，被称为双峰雷蒙德隆起。通过数值模拟，利用各向异性全斯托克斯热机械流求解器，分析了Kealey冰升的演化过程及其所涉及的时间尺度。我们得出结论，Kealey冰隆起的地层特征至少需要3 ka的近静止流动条件。然而，我们不能排除在上个世纪最近一次流量重组的可能性。我们强调，在Kealey冰升中观测到的雷达地层学中的静止流动迹象已经在East Ellsworth Land地区的其他冰裂缝中观测到，表明该地区在千年时间尺度上存在静止流动条件。
Abstract Flow at ice divides, their shape, size and internal structure depend not only on local conditions, but also on the flow regimes and past histories of the surrounding ice masses. Here we use field data from Kealey Ice Rise, Ellsworth Land, West Antarctica, in combination with flow modelling to investigate any possible signs of transients in the flow of the surrounding ice masses. Kealey Ice Rise shows linear surface features running parallel to its ridge in satellite imagery and a conspicuous layering in the ground-penetrating radar data known as double-peaked Raymond bumps. Through numerical modelling, by using an anisotropic full-Stokes thermomechanical flow solver, we analyse the evolution of Kealey Ice Rise and the timescales involved. We conclude that the features observed in the stratigraphy of Kealey Ice Rise require at least 3 ka of near-stationary flow conditions. However, we cannot exclude the possibility of a recent flow reorganization in the last century. We stress that the signs of stationary flow in radar stratigraphy observed in Kealey Ice Rise have been observed in other ice divides in the East Ellsworth Land area, suggesting stationary flow conditions over a millennial timescale in the region.