Crustal earthquake bursts in California and Japan: Their patterns and relation to volcanoes
Crustal earthquake bursts in California and Japan: Their patterns and relation to volcanoes
复制标题
加利福尼亚和日本的地壳地震爆发：其模式及其与火山的关系
DOI：
10.1029/2006gl027723
复制
发表时间：
2006
影响因子：
5.2
通讯作者：
P. Shearer
中科院分区：
文献类型：
--
作者：
J. Vidale;K. Boyle;P. Shearer
我们分析了加州南部和日本的153次地震爆发。加州南部和日本的爆发模式相似;它们填补了没有明显主震的“群状”序列和带有大森定律余震的主震之间的频谱。与我们以前的工作一致，与“主震-余震”型序列相比，日本的“群状”序列有更多的事件，体积更大，并且倾向于随时间扩展。在这两个地区，我们发现，从最大事件开始的序列往往持续时间要短得多。火山50公里范围内的爆发在性质上与其他地方相似，只是它们往往持续时间更长。我们假设，swarminess是流体压力重新分布和/或驱动地震活动性爆发的地震滑动的代理，相反，主震余震型序列的端部构件行为仅由一系列弹性失效引起。空间地震活动性分布的复杂性与观察到的群的类型无关，这表明在确定我们观察到的模式时，流体条件和成分可能比几何形状更有影响力。
We analyze 153 bursts of earthquakes in southern California and Japan. The burst patterns are similar in southern California and Japan; they fill a spectrum between “swarm‐like” sequences without obvious mainshocks and mainshocks with Omori‐law‐abiding aftershocks. In agreement with our previous work, the “swarm‐like” sequences in Japan have more events, are more voluminous, and tend to expand with time, when compared to “mainshock‐aftershock” type sequences. In both regions, we find that the sequences starting with their largest events tend to be much shorter in duration. Bursts within 50 km of volcanoes are similar in character to those elsewhere except they tend to have longer duration. We hypothesize that swarminess is a proxy for fluid pressure redistribution and/or aseismic slip driving the seismicity bursts, and conversely, the mainshock‐aftershock‐style sequences have end‐member behavior that results solely from a cascade of elastic failures. The complexity of the spatial seismicity distribution does not correlate with the style of swarm observed, indicating that fluid conditions and composition are likely more influential than geometry in determining the patterns we observe.