Mechanism of deep low frequency earthquakes: Further evidence that deep non-volcanic tremor is generated by shear slip on the plate interface
Mechanism of deep low frequency earthquakes: Further evidence that deep non-volcanic tremor is generated by shear slip on the plate interface
复制标题
DOI：
10.1029/2006gl028890
复制
发表时间：
2007-02-15
影响因子：
5.2
通讯作者：
Beroza, Gregory C.
中科院分区：
文献类型：
--
作者：
Ide, Satoshi;Shelly, David R.;Beroza, Gregory C.
我们研究日本四国西部南海海槽低频地震（LFE）的机制。先前的精确位置表明它们代表了板块边界上的剪切滑移。在本文中，我们研究了这些事件的机制。由于信噪比较低，我们分析了叠加的 LFE 波形，并将其与俯冲菲律宾海板块内已知机制的附近地震的波形进行比较。对P波初动震源机制和S波形矩张量的分析表明，LFE代表了向西北倾斜的低角度逆冲断层（即板块界面）上的剪切滑移。结合深部震颤由大量 LFE 组成的报道，我们的结果表明深部震颤是由板块界面上的剪切滑移直接产生的，因此代表了伴随的慢滑移事件的地震特征。
We study the mechanism of low frequency earthquakes (LFEs) in the Nankai Trough in western Shikoku, Japan. Precise locations have previously suggested that they represent shear slip on the plate boundary. In this paper we examine the mechanism of these events. Due to the low signal-to-noise ratio, we analyze stacked LFE waveforms and compare them with the waveforms of nearby earthquakes of known mechanism within the subducting Philippine Sea Plate. Analysis of both the focal mechanism using P-wave first-motions and the moment tensor using S waveforms indicates that LFEs represent shear slip on a low-angle thrust fault dipping to the northwest, namely the plate interface. Together with reports that deep tremor consists of a swarm of LFEs, our results suggest that deep tremor is generated directly by shear slip on the plate interface, and as such represents a seismic signature of the accompanying slow slip events.