Study of the dynamic state of ice shelves on the south-western Antarctic Peninsula by an interdisciplinary approach of remote sensing, fracture mechanics and modelling of ice dynamics

该项目旨在了解南极半岛西南部威尔金斯冰架和乔治六世冰架正在发生的和潜在的变化。两者都位于假定的冰架生存能力的气候极限区域，并且已经显示出相当大的冰锋退缩。2008年发生在威尔金斯冰架上的冰架破裂事件说明了冰架解体的可能性。我们提出了一种多机构、跨学科的方法，包括遥感、冰动力学建模和断裂力学，旨在提高对温度升高对冰架稳定性影响的理解。遥感组件将包括威尔金斯冰架的表面结构和裂缝发展随时间的映射，以及通过SAR干涉测量和特征跟踪对两个冰架的表面速度场的推导，这些都需要作为裂缝和冰动力学建模的输入数据集。为此，将使用多时相光学和SAR图像。观测到的量将在冰动力学和断裂力学的背景下进行解释。冰川学模拟部分包括一个浅层冰架近似下的冰架流动热力一致性动力学模型，该模型将应用于两个冰架。为了了解对外部变化的响应，将测试模型对流入速度、热边界条件和接地面积的敏感性。我们特别注重在模型中加入局部特征，例如威尔金斯冰架上的裂缝。该项目的断裂力学部分将侧重于破坏冰架并导致破裂事件的关键情况。

This project aims to gain understanding of ongoing and potential changes of Wilkins and GeorgeVI ice shelves on the south-western Antarctic Peninsula. Both are located in an area of the supposed climatic limit of viability of ice shelves and have already shown considerable ice front retreat. The break-up events in 2008 on Wilkins Ice Shelf exemplified their potential of disintegration. We propose a multi-institutional, interdisciplinary approach including remote sensing, modelling of the ice dynamics and fracture mechanics with the aim to improve the understanding of the impacts of temperature increase on ice shelf stability. The remote sensing component will include the mapping of surface structures and fracture development over time for Wilkins Ice Shelf, as well as the derivation of surface velocity fields by SAR interferometry and feature tracking for both ice shelves, required as input datasets for modelling of fracture and ice dynamics. For this purpose, multi-temporal optical and SAR imagery will be used. The observed quantities will be interpreted in the context of ice dynamics and fracture mechanics. The glaciological modelling component includes a thermo-dynamical consistent dynamic model for ice shelf flow in shallow shelf approximation, which will be applied to both ice shelves. The model sensitivity to inflow speeds, thermal boundary conditions and grounded areas will be tested in order to gain understanding of the response to external changes. We specially focus on the incorporation of local features, e.g. rifts on Wilkins Ice Shelf, in the model. The fracture mechanic component of the project will focus on critical situations which damage the ice shelves and which lead to break-up events.