Field Studies and Modeling of the Breakup of Antarctic Sea Ice

该项目研究南极海冰覆盖层如何对风和海浪施加的应力作出反应，以及海冰内的温度分布如何影响这些反应。 将对麦克默多海峡海冰的变形和断裂进行实验，方法是施加一系列受控应力并观察其效果。 众所周知，大浮冰不会以与小浮冰相同的方式断裂，因此有必要在数十米的尺度上进行实验，以便有效地将断裂过程外推到更大的尺度上，从而应用于破冰的工程问题。 这项研究的关键要素是获得有关冰的微观结构的详细信息，例如晶体结构，盐水通道和冰结构中的其他缺陷，并具有良好的理论框架来指导实验工作和随后的模型开发。 一个关键的影响是冰内微裂纹的产生和增长。 这项工作的一个组成部分将与新西兰南极计划联合进行。 这涉及到疲劳裂纹扩展的断裂力学，利用微观结构的观察，以验证磁共振测量的冰中夹杂物的结构，和断裂区的声发射。

This project is a study of how the antarctic sea ice cover responds to stresses applied by wind and ocean waves, and how the temperature distribution within the sea ice affects these responses. Experiments will be conducted on the deformation and fracture of sea ice occurring in McMurdo Sound by applying a series of controlled stresses and observing their effects. It is known that large ice floes do not fracture in the same way as small ones do, therefore it is necessary to carry out experiments on the scale of tens of meters in order to validly extrapolate the fracture process to the larger scales that have applications to engineering problems of breaking ice. The crucial elements for this study are the obtaining of detailed information on the microstructure of the ice, such as crystal structure, brine channels, and other flaws in the ice fabric, and having a sound theoretical framework to guide the experimental work and subsequent model development. A key effect is the initiation and growth of microcracks within the ice. One component of the work will be carried out jointly with the New Zealand Antarctic program. This concerns the fracture mechanics of fatigue crack propagation, the utilization of microstructural observations to verify magnetic resonance measurements of the structure of inclusions in the ice, and the acoustic emissions of fracture zones.