床上的摩擦并不能控制冰川的快速流动
L A Stearns1,2, C J van der Veen3
1Department of Geology, University of Kansas, Lawrence, KS 66045, USA. stearns@ku.edu.
概括
目前的冰盖模型无法准确预测海平面上升, 新分析显示滑动速度与冰床界面的净压力有关, 而不是摩擦应力.
科学领域:
- 冰川学
- 气候科学
- 地球系统科学
背景情况:
- 冰盖模型对于预测海平面上升至关重要.
- 在冰床接口的基底滑动是控制冰流的关键因素.
- 目前的模型通常使用过时的滑动参数化,用于硬床.
研究的目的:
- 研究冰盖模型中使用的当前基底滑动参数的有效性.
- 分析基底滑动与格陵兰冰床界面的应力之间的关系.
- 将发现与现有理论和观测山脉冰川进行比较.
主要方法:
- 分析140个格陵兰冰川的基底滑动数据.
- 检查滑动速度和摩擦应力之间的关系.
- 研究滑动速度与冰川床的净压力之间的相关性.
主要成果:
- 硬床的理论滑动关系不适用于分析的格陵兰冰川.
- 在基底滑动和摩擦应力之间没有发现显著的关系.
- 滑动速度与冰川床的净压力之间存在很强的相关性.
结论:
- 由于基底滑动假设不准确,现有的冰盖模型可能会高估或低估未来的海平面上升.
- 滑动速度和净压力之间的关系为基底滑动提供了更准确的参数化.
- 为了改善海平面上升的预测,对基底过程的进一步研究至关重要.
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