Present stability of the Larsen C ice shelf, Antarctic Peninsula
Present stability of the Larsen C ice shelf, Antarctic Peninsula
复制标题
DOI：
10.3189/002214310793146223
复制
发表时间：
2010-01-01
影响因子：
3.4
通讯作者：
Glasser, N. F.
中科院分区：
文献类型：
--
作者：
Jansen, D.;Kulessa, B.;Glasser, N. F.
我们模拟了流动的拉森C和最北端的拉森D冰架，南极半岛，使用冰流的连续介质力学模型，并应用断裂准则的模拟速度，调查冰架的现今稳定性。制约因素来自2008/09年南半球夏季的卫星数据和地球物理测量。冰架厚度是由BEDMAP和ICESat数据得出的，密度-深度关系是由我们的原位地震反射数据推断的。我们得到了很好的协议之间的模拟和测量的冰流速，并推断和观察裂缝和裂缝的分布。预测断裂区域和观察到的裂缝之间的剩余差异集中在我们假设大量海冰的区域，因此改变了冰柱的机械性能。这强调了这些区域的重要性，并表明需要更多的数据来了解它们对冰架稳定性的影响。模拟的流速和相应的应力分布表明，拉森C冰架是稳定的时刻。然而，由于与北方入口和凯尼恩半岛南部较慢的部分脱钩，细长海洋冰区的减弱可能导致冰架加速，导致与拉森B冰架解体前的速度分布相似。
We modelled the flow of the Larsen C and northernmost Larsen D ice shelves, Antarctic Peninsula, using a model of continuum mechanics of ice flow, and applied a fracture criterion to the simulated velocities to investigate the ice shelf's present-day stability. Constraints come from satellite data and geophysical measurements from the 2008/09 austral summer. Ice-shelf thickness was derived from BEDMAP and ICESat data, and the density-depth relationship was inferred from our in situ seismic reflection data. We obtained excellent agreements between modelled and measured ice-flow velocities, and inferred and observed distributions of rifts and crevasses. Residual discrepancies between regions of predicted fracture and observed crevasses are concentrated in zones where we assume a significant amount of marine ice and therefore altered mechanical properties in the ice column. This emphasizes the importance of these zones and shows that more data are needed to understand their influence on ice-shelf stability. Modelled flow velocities and the corresponding stress distribution indicate that the Larsen C ice shelf is stable at the moment. However, weakening of the elongated marine ice zones could lead to acceleration of the ice shelf due to decoupling from the slower parts in the northern inlets and south of Kenyon Peninsula, leading to a velocity distribution similar to that in the Larsen B ice shelf prior to its disintegration.