隐藏的地震冰流变形级联
Andreas Fichtner1, Coen Hofstede2, Brian L N Kennett3
1Department of Earth and Planetary Sciences, ETH Zurich, Zurich, Switzerland.
概括
冰流是海平面变化的主要调节者, 这些由杂质驱动的布会显著影响延展率,改善冰盖模型.
科学领域:
- 冰川学
- 固体地球地质学
- 海平面变化
背景情况:
- 冰流对于调节海平面变化至关重要.
- 由于过程不确定性,目前的粘流模型无法充分预测冰流的演变.
- 格陵兰冰流的脆弱变形模式挑战了现有的模型.
研究的目的:
- 研究格陵兰冰流中观察到的脆性变形模式.
- 了解冰川地震在冰川流动中的作用.
- 弥合冰盖模型与地质观测之间的差距.
主要方法:
- 在格陵兰冰流中利用钻孔光纤观测.
- 分析了冰川的地震级流及其在杂质附近的核形成.
- 估计了地震级联应变率,并将其与地质测量进行了比较.
主要成果:
- 发现冰川式冰川级地震是一种与粘性流不相容的脆弱变形模式.
- 确定了与火山活动相关的杂质作为谷物边界裂和布的核部位.
- 估计的地震级流对应应变率相当于地质测量.
结论:
- 冰震级流代表了冰流中以前未经建模的重大变形过程.
- 这种脆弱的可塑性机制为目前的冰盖模型中的差异提供了合理的解释.
- 这些发现有助于更好地了解冰流的动态及其对海平面调节的影响.
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