Quantifying Glacial Erosion Rates, Magnitudes, and Paleotopography in the Coast Mountains, British Columbia

量化冰川侵蚀速率、强度和海岸山脉的古地形，不列颠哥伦比亚省P·I·托德·A·埃勒斯-密歇根大学EAR-0309779在过去12年里，一场全球性的科学辩论接踵而至，即气候变化或构造运动是否为加速山体抬升的现象或现实提供了推动力。密歇根大学的这个为期三年的项目将检验这样一个假设，即气候变冷，更具体地说，冰川作用，增加了山脉的地形起伏和最大高度，从而在过去的1000万年里产生了加速隆起的现象。由于缺乏对冰川侵蚀在百万年时间尺度上的分布和数量的了解，以前对这一假说进行检验的尝试受到了阻碍。这项研究将把地球化学数据(低温温度计时仪)与三维计算机模型结合起来，以量化不列颠哥伦比亚省南部海岸山脉的冰川侵蚀历史。为这项研究整合新的数据收集和建模将涉及几个步骤。(1)两个季节的实地考察将在南海岸山脉约25x25公里的区域内提供60个新样本。(2)需要两年的计算机程序开发来修改现有的三维计算机模型以模拟不断演变的地形。该模型将预测各种构造和侵蚀情景下的暴露样品年龄。(3)最后两年将应用一个反向计算机模拟程序，以确定满足测量的地球化学样品年龄的冰川侵蚀历史和古代冰前地形的范围。这三个步骤的结果将通过重建海岸山脉冰川之前的山脉地形来检验所述的假设，并评估冰川是否增加了地形起伏。除了解决科学界长期存在的问题外，这项研究还将为一名研究生提供博士学位。这位首席研究员和研究生将在K-12学校的科学课程上定期讲授冰川和冰河时代，至少有一名本科生将参与并在研究过程中得到指导。

Quantifying Glacial Erosion Rates, Magnitudes, and Paleotopography in the Coast Mountains, British ColumbiaP.I. Todd A. Ehlers - University of MichiganEAR-0309779In the last 12 years a global scientific debate has ensued over if climate change or tectonics provided the impetus for the appearance, or reality of accelerated mountain uplift. This three year project at the University of Michigan will test the hypothesis that cooler climates, and more specifically glaciation, increase the topographic relief and maximum height of mountain ranges, thereby producing the appearance of accelerated uplift in the last ~10 Million years. Previous attempts to test this hypothesis have been hampered by a lack in understanding of the distribution and amount of glacial erosion over million-year time scales. This study will integrate geochemical data (low-temperature thermochronometers) with three-dimensional computer models to quantify the glacial erosion history in the southern Coast Mountains, B.C.The integration of new data collection and modeling for this study will involve several steps. (1) Two seasons of fieldwork will provide 60 new samples within a ~25x25 km area of the southern Coast Mountains. (2) Two years of computer program development are needed to modify an existing three-dimensional computer model to simulate evolving topography. The model will predict exposed sample ages under a variety of tectonic, and erosional scenarios. (3) The last two years will apply an inverse computer-modeling program to determine the range of glacial erosion histories, and ancient preglacial topographies, that satisfy the measured geochemical sample ages. The results from these three steps will test the stated hypothesis by reconstructing the mountain topography prior to glaciation in the Coast Mountains and assess if glaciation increased topographic relief. In addition to addressing a long-standing problem in the scientific community, this study will also provide a Ph.D. for one graduate student. The principle investigator and graduate student will give regular talks in K-12 school science classes on 'glaciers and ice ages' and at least one undergraduate student will be involved, and mentored in the research process.