在阿拉斯加冰川中测量的三维变形
1J. T. Harper and N. F. Humphrey, Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, USA. W. T. Pfeffer, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
概括
冰川流动是复杂的,大部分运动发生在床上. 冰的变形速度随着深度而变化,但独立于滑动速度,挑战了简单的模型.
科学领域:
- 冰川学的冰川学
- 地质物理学 地质物理学
- 地球科学 地球科学 地球科学
背景情况:
- 温带山谷冰川表现出复杂的流动动力学.
- 了解冰川运动对于预测海平面上升和水资源至关重要.
研究的目的:
- 为了研究沃灵顿冰川的三维冰流场.
- 为了确定基底滑动和内部冰变形对冰川运动的贡献.
- 评估常见的建模假设的有效性,如平面应变.
主要方法:
- 使用28个钻孔测量冰的运动.
- 分析表面运动和冰层内的应变速率.
- 三维流场的特征. 三维流场的特征.
主要成果:
- 基底滑动占冰川表面运动的60-70%.
- 在上方120米处,冰的延伸率很低,在床上迅速增加.
- 内部冰的变形与基底滑动速率的时间变化没有相关性.
结论:
- 沃灵顿冰川表现出显著的基底滑动.
- 平面应变对于建模这个冰川的粘性流动来说是一个不充分的假设.
- 详细的3D测量对于准确的冰川流量建模至关重要.
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