Large Scale Glacial Erosion and Debris Production

虽然已经开发了孤立的冰川侵蚀模型，但还没有认真尝试将这种工作与冰川流动模型结合起来，以提供对冰川地貌演变的更大规模问题的定量洞察。此外，这些分析几乎没有为准确处理冰川侵蚀产生的碎片提供指导，然而，冰川底部的碎片最近在现代冰川动力学考虑中成为一个中心未知数。基于对冰川磨损和采摘(采石)物理的基本分析，以及在蒙大拿州格林内尔冰川底部的实地观察，将建立冰川侵蚀的定量模型。最初的理论工作表明，滑动速度、基础有效压力和采石率之间存在物理上的关系。进一步的采石理论工作，加上对Hallet(1981)磨损模型的改进，将提供一个全面的冰川侵蚀模型。该侵蚀模型将与冰川流有限元程序相结合，用于模拟U形山谷等冰川地貌的发育，模拟碎片产生的空间模式，并跟踪碎片在冰川和冰盖中的运移。

Although isolated glacial erosion models have been developed, there has been no serious attempt to combine such work with models of glacier flow to provide quantitative insight into larger scale problems of glacial land-form evolution. Moreover, these analyses offer little guidance for a precise treatment of debris production by glacial erosion, and yet debris at the base of glaciers has recently emerged as a central unknown in modern considerations of glacier dynamics. A quantitative model of glacial erosion will be developed based on a fundamental analysis of the physics of glacial abrasion and plucking (quarrying), and field observations at the base of Grinnell Glacier, Montana. Initial theoretical work suggests a physically based relationship between sliding velocity, basal effective pressure and rate of quarrying. Further theoretical work on quarrying, in combination with improvements on Hallet's (1981) abrasion model will provide an overall glacial erosion modelling. This erosion model will be coupled with finite element programs for glacier flow, and used to simulate the development of glacial land-forms such as U-shaped valleys, model spatial patterns of debris production, and tracking debris transport in glaciers and ice sheets.