A Laboratory Study of Texture Development During Grain Size Sensitive Creep of Ice, with Applications to the Flow of Glaciers and Ice Sheets

该奖项支持一个进行实验室实验的项目，以研究冰在超塑性流动过程中形成的纹理。超塑性流动是最近在实验室中被发现的，可以被认为是一种新的冰流动机制。对这些从实验室到自然条件下的超塑性流动的新数据进行简单的外推，表明冰川和冰盖的流动就是通过这种机制进行的。此外，在实验室中，在超塑性流动过程中产生的冰的一些粒度特征（例如晶体形状）与在冰川和冰盖中观察到的非常相似。然而，尽管有了这一令人兴奋的发现，在我们能够充分自信地将这些新的流动数据应用于冰川和冰盖流动的数学模型之前，仍然存在重要的问题。在实验室研究中看到的结构将与在冰川和冰盖的实地研究中观察到的结构进行比较。这些比较，再加上来自实验室的新超塑性流动数据与来自实地研究的流动测量数据的比较，将为进一步评估自然界超塑性流动的重要性提供一个有力的方法，从而提高我们对冰川和冰盖动力学以及全球气候变化的理解。实验将由PI和一名本科生研究助理进行。实验结果将发表在相关的期刊上，在冰川学会议上提出，并纳入课程作业。

This award supports a project to conduct laboratory experiments to investigate textures formed in ice during superplastic flow. Superplastic flow has recently been discovered in the laboratory and can be considered a new flow mechanism for ice. A simple extrapolation of these new data for superplastic flow from laboratory to natural conditions suggests that glaciers and ice sheets flow via this mechanism. Furthermore, several grain-scale features in ice (e.g., crystal shape) produced during superplastic flow in the laboratory are remarkably similar to those observed in glaciers and ice sheets. Despite this exciting discovery, however, important questions remain before we can apply with full confidence these new flow data in mathematical models of glacier and ice sheet flow. The textures seen in laboratory studies will be compared with those observed in field studies of glaciers and ice sheets. These comparisons, coupled with comparisons of the new superplastic flow data from the laboratory with flow measurements from field studies, will provide a powerful method for further assessing the importance of superplastic flow in nature and thereby improve our understanding of glacier and ice sheet dynamics and global climate change. Experiments will be conducted by the PI and an undergraduate research assistant. Experimental results will be published in relevant refereed journals, presented at glaciology meetings and incorporated into coursework.