Characteristic silent earthquakes in the eastern part of the Boso peninsula, Central Japan
Characteristic silent earthquakes in the eastern part of the Boso peninsula, Central Japan
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日本中部房总半岛东部特征性无声地震
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
M. Murakami
中科院分区：
文献类型：
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作者：
S. Ozawa;S. Miyazaki;Y. Hatanaka;T. Imakiire;M. Kaidzu;M. Murakami
全球定位系统（GPS）数据的分析表明，在房总半岛，日本中部，从2002年10月约50天的瞬态地壳变形。在1996年类似事件发生6年后，检测到的东南向水平位移表明菲律宾海板块和北美板块之间发生了板间滑动。我们估计，在房总半岛附近有一个矩震级（Mw）为6.6的地震滑动区，与相关的地震活动相邻。2002年季风滑动的滑动演化始于10月4日，自北向南迁移了10天左右，之后逐渐下沉，并重新开始滑动，持续到12月2日，并进一步向南传播。1996年和2002年两次地震在震源区和滑动过程上的相似性表明，房总地震滑动是典型的无声地震，而且每6 ~ 7年在同一地区重复发生一次震群。一个更紧密耦合的南部地区，没有释放足够的能量，在1996年的事件可能造成的差异，在1996年和2002年的事件之间的震级，中央滑动面积和持续时间，如果假设的复发间隔应变积累是真的，基于群地震活动。
Analysis of Global Positioning System (GPS) data shows transient crustal deformation in the Boso peninsula, central Japan, for about fifty days from October 2002. The southeastward horizontal displacements detected suggest the occurrence of interplate aseismic slip between the Philippine Sea plate and the North American plate, six years after a similar event in 1996. We estimate an area of aseismic slip with moment magnitude (Mw) 6.6 centered off the Boso peninsula, adjacent to associated seismic activity. Slip evolution of the 2002 aeismic slip started on October 4 and migrated from north to south for about ten days, followed by gradual subsidence and restarting of slip which lasted until ∼December 2, propagating more southward. Similarities in focal area and slip process between the 1996 and the 2002 events suggest the Boso aseismic slips as characteristic silent earthquakes, together with the repetitive occurrence of seismic swarm in a similar region every six to seven years. A more tightly coupled southern area that did not release enough energy in the 1996 event may have caused the differences in magnitude, central slip area, and duration between the 1996 and the 2002 events, if the hypothesized recurrence interval for strain accumulation is true, based on swarm seismicity.