Remote Triggering Not Evident Near Epicenters of Impending Great Earthquakes
Remote Triggering Not Evident Near Epicenters of Impending Great Earthquakes
复制标题
即将发生的大地震震中附近远程触发并不明显
DOI：
10.1785/0120120126
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发表时间：
2013
影响因子：
3
通讯作者：
T. Lay
中科院分区：
文献类型：
--
作者：
N. V. Elst;E. Brodsky;T. Lay
最近，发生了许多破坏性的大地震（MW ≥8），过去七年的地震率是111年地震历史平均地震率的260%。每一次大地震都提供了一个机会，可以在推断的地震周期的开始和结束时研究一个主要断层。在这项工作中，我们使用这些事件作为目标和源探测敏感性的动态触发在震中地区之前和之后的大地震。这项研究还仔细讨论了大地震在一系列远程触发序列中相互作用的可能性，这些序列最终导致进一步的大地震。我们使用区域和全球地震目录来测量事件间隔时间统计的变化，寻找与1998年至2011年发生的16次MW ≥8的大地震相关的触发证据。统计意义的计算相对于一个非平稳的参考模型，包括主震余震集群。我们发现有限的证据表明，一些大地震引发了地震活动的增加，在该序列中的下一个大地震的网站。然而，这一证据并没有得到所有统计检验和所有地震目录的证实。在95%的置信水平下，每次大地震前几年到几十年的系统触发率变化小于19%，太小而无法解释观察到的速率增加。目录不足以解决以前研究中预期的更温和的触发。我们计算出，完整性震级从3.7提高到3.5可以解决国际地震中心（ISC）目录中作为一个整体的预期触发信号，但需要提高到M2.0，以一致地解决区域触发。
Recently, there have been numerous great ( M w≥8), devastating earthquakes, with a rate in the last seven years that is 260% of the average rate during the 111‐year seismological history. Each great earthquake presents an opportunity to study a major fault at the very beginning and end of the inferred seismic cycle. In this work, we use these events as both targets and sources to probe susceptibility to dynamic triggering in the epicentral region before and after a large earthquake. This study also carefully addresses the possibility that large earthquakes interact in a cascade of remotely triggered sequences that culminates in further large earthquakes. We seek evidence of triggering associated with the 16 great M w≥8 events that occurred between 1998 and 2011, using regional and global earthquake catalogs to measure changes in interevent time statistics. Statistical significance is calculated with respect to a nonstationary reference model that includes mainshock–aftershock clustering. We find limited evidence that a few great earthquakes triggered an increase in seismicity at the site of the next great earthquake in the sequence. However, this evidence is not corroborated by all statistical tests nor all earthquake catalogs. Systematic triggered rate changes in the years to decades before each great earthquake are less than 19% at the 95% confidence level, too small to explain the observed rate increase. The catalogs are insufficient for the purpose of resolving more moderate triggering expected from previous studies. We calculate that an improvement in completeness magnitude from 3.7 to 3.5 could resolve the expected triggering signal in the International Seismic Center (ISC) catalog taken as a whole, but an improvement to M 2.0 would be needed to consistently resolve triggering on a regional basis.