Reassessing the 2006 Guerrero slow-slip event, Mexico: Implications for large earthquakes in the Guerrero Gap
Reassessing the 2006 Guerrero slow-slip event, Mexico: Implications for large earthquakes in the Guerrero Gap
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重新评估 2006 年墨西哥格雷罗慢滑事件：对格雷罗峡大地震的影响
DOI：
10.1002/2014jb011557
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发表时间：
2015
期刊：
影响因子：
3.4
通讯作者：
Bekaert D
中科院分区：
文献类型：
--
作者：
Bekaert D
在墨西哥的格雷罗，在一个地震空区观察到了慢滑事件，自1911年以来没有发生过地震。今天整个缺口的破裂可能会导致Mw8.2 -8.4级地震。然而，目前尚不清楚慢滑事件如何改变格雷罗地震区的应力场，以及它们对破坏性地震的影响。大多数早期的研究都依赖于全球导航卫星系统测量的稀疏网络。在这里，我们表明，干涉合成孔径雷达可以用来提高空间分辨率。我们发现，由于2006年的慢滑事件的滑动进入孕震区和格雷罗差距，与0.5厘米的滑动达到浅至12公里。我们发现慢滑与一个高度耦合的区域相关，并估计自2001/2002年慢滑事件（4.7年）结束以来，慢滑事件使总累积力矩减少了1.50%。然而，即使考虑到缓慢的下滑，格雷罗缺口的瞬时赤字每年增加Mw 6.8。因此，格雷罗缺口仍有发生大地震的可能性，在过去世纪累积的滑动亏损相当于Mw 8.15。慢滑区和非火山震颤之间的相关性，以及慢滑和超低速层之间的相关性，支持可能与高孔隙压力相关的共同震源的假设。
In Guerrero, Mexico, slow‐slip events have been observed in a seismic gap, where no earthquakes have occurred since 1911. A rupture of the entire gap today could result in aMw8.2–8.4 earthquake. However, it remains unclear how slow‐slip events change the stress field in the Guerrero seismic region and what their implications are for devastating earthquakes. Most earlier studies have relied on a sparse network of Global Navigation Satellite Systems measurements. Here we show that interferometric synthetic aperture radar can be used to improve the spatial resolution. We find that slip due to the 2006 slow‐slip event enters the seismogenic zone and the Guerrero Gap, with ∼5 cm slip reaching depths as shallow as 12 km. We show that slow slip is correlated with a highly coupled region and estimate that slow‐slip events have decreased the total accumulated moment since the end of the 2001/2002 slow‐slip event (4.7 years) by ∼50%. Nevertheless, even accounting for slow slip, the moment deficit in the Guerrero Gap increases each year byMw∼6.8. The Guerrero Gap therefore still has the potential for a large earthquake, with a slip deficit equivalent toMw∼8.15 accumulated over the last century. Correlation between the slow‐slip region and nonvolcanic tremor, and between slow slip and an ultraslow velocity layer, supports the hypothesis of a common source potentially related to high pore pressures.