Quantifying the role of marine ice in Larsen C ice shelf dynamics

南极大陆被冰架环绕，冰架是冰川和冰流的浮动延伸，在冰盖和海洋之间提供了重要的缓冲。冰架的坍塌已被证明允许内陆冰加速，从而导致海平面上升。之前的坍塌没有完全解释，部分原因是冰架的结构现在才被理解。在这个小项目中，我们将重点关注冰架结构的一个新方面，这可能是它们稳定性的基础。在两个供应冰架的冰川汇合的地方，它们之间的冰很薄，水可以冻结在冰块的底部，形成一条“海洋冰”，然后随着冰架流向开阔的海洋，与冰川(或“流星”)冰夹带在一起。海冰比流星冰更温暖、更柔软、更具渗透性，因此可以提供需要更好理解的薄弱带。我们将使用我们在过去两个季节收集的独特的穿透冰层雷达数据、我们多年来开发的遥感技术以及冰架建模方面的具体专业知识，调查南极半岛拉森C冰架的这一方面。在该项目的8个月内，我们将能够测试海洋冰带在南极冰架形成的稳定性中的重要性。

The Antarctic continent is fringed by ice shelves, the floating extensions of glaciers and ice streams, which provide an important buffer between the ice sheets and the ocean. The collapse of ice shelves has been shown to allow inland ice to accelerate, thus leading to sea level rise. Previous collapses are not completely explained, partly because the structure of ice shelves is only now being understood. In this small project we will focus on an emerging aspect of ice shelf structure which may be fundamental to their stability. Where two ice-shelf-feeding glaciers merge, the ice between them is thin and water can freeze onto the base of this ice to form a band of 'marine ice' which is then entrained with the glacier (or 'meteoric') ice as it flows with the ice shelf towards the open ocean. Marine ice is warmer, softer, and more permeable than meteoric ice and can therefore provide bands of weakness which need to be better understood. We will investigate this aspect of the Larsen C ice shelf on the Antarctic Peninsula using unique ice-penetrating radar data that we have collected over the last two seasons, remote sensing techniques that we have been developing for many years, and specific expertise in ice shelf modelling. Within the eight months of the project we will be able to test the importance of marine ice bands in the stability of Antarctic ice shelves where they form.