Uncovering the geodetic signature of silent slip through repeating earthquakes
Uncovering the geodetic signature of silent slip through repeating earthquakes
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DOI：
10.1002/2015gl063685
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发表时间：
2015-04-28
影响因子：
5.2
通讯作者：
Campillo, Michel
中科院分区：
文献类型：
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作者：
Frank, William B.;Radiguet, Mathilde;Campillo, Michel
沿着板块界面深根释放应力的缓慢瞬态滑动最常见于安装在地表的区域 GPS 网络。如果沿断层深度的位错没有产生大于观测噪声水平的大地测量信号，那么慢滑移的检测就不是微不足道的。我们没有使用比较独立收集的地震和大地测量观测来研究慢滑移的典型工作流程，而是使用重复的低频地震来揭示以前未观测到的慢滑移事件。通过将 GPS 时间序列与低频地震活动和叠加事件对齐，我们识别出重复的瞬态滑动事件，该事件会在叠加之前在表面产生隐藏在噪声下的位移。我们的结果表明，地震信息引导下的瞬态滑移大地测量对于探索断层滑移谱至关重要。
Slow transient slip that releases stress along the deep roots of plate interfaces is most often observed on regional GPS networks installed at the surface. The detection of slow slip is not trivial if the dislocation along the fault at depth does not generate a geodetic signal greater than the observational noise level. Instead of the typical workflow of comparing independently gathered seismic and geodetic observations to study slow slip, we use repeating low-frequency earthquakes to reveal a previously unobserved slow slip event. By aligning GPS time series with episodes of low-frequency earthquake activity and stacking, we identify a repeating transient slip event that generates a displacement at the surface that is hidden under noise prior to stacking. Our results suggest that the geodetic investigation of transient slip guided by seismological information is essential in exploring the spectrum of fault slip.