The Mw 6.5 offshore Northern California earthquake of 10 January 2010: Ordinary stress drop on a high‐strength fault
The Mw 6.5 offshore Northern California earthquake of 10 January 2010: Ordinary stress drop on a high‐strength fault
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2010 年 1 月 10 日北加州近海 6.5 级地震：高强度断层上的普通应力下降
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
J. McGuire
中科院分区：
文献类型：
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作者：
M. Wei;J. McGuire
2010年1月10日发生在北方加州近海的6.5级地震是全球定位系统网络首次很好地捕捉到的海洋岩石圈板内地震之一。它提供了一个机会，以评估断裂力学的高强度故障。同震位移的静态反演表明，滑动峰值与预期强度包络线相同的深度，其中差应力可高达600 MPa。橄榄岩的实验室实验预测在这些条件下会发生剧烈的动态弱化。观测到的正常应力降（2-20 MPa）可能表明岩石圈比强度包络预测的要弱得多，或者在破裂过程中没有发生实验室中观察到的破坏机制。GPS观测结果表明，震后信号非常少，这表明如果在同震破裂下方存在剪切带，则它的应力水平明显大于同震应力变化。
The 10 January 2010 Mw 6.5 earthquake offshore Northern California is one of the first intraplate earthquakes in oceanic lithosphere to be well captured by a GPS network. It presents an opportunity to evaluate rupture mechanics on a high‐strength fault. Static inversion of the coseismic displacements shows that the slip peaks at the same depth as the expected strength envelope, where the differential stresses can be as high as 600 MPa. Laboratory experiments on peridotite predict dramatic dynamic weakening at these conditions. The observed ordinary stress drop, 2–20 MPa, may indicate that the lithosphere is much weaker than strength envelope predicts or that the failure mechanisms seen in the laboratory are not occurring during the rupture. The GPS observations show very little postseismic signal indicating that if a shear zone exists beneath the coseismic rupture, it operates at significantly greater stress levels than the coseismic stress change.