Weak interplate coupling by seamounts and repeating M ∼ 7 earthquakes
Weak interplate coupling by seamounts and repeating M ∼ 7 earthquakes
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DOI：
10.1126/science.1160250
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发表时间：
2008-08-29
期刊：
影响因子：
56.9
通讯作者：
Kanazawa, Toshihiko
中科院分区：
文献类型：
--
作者：
Mochizuki, Kimihiro;Yamada, Tomoaki;Kanazawa, Toshihiko
俯冲海山被认为会增加俯冲板块和俯冲板块之间的法向应力。然而，最近的地震调查和实验室实验表明，板间耦合很弱。日本海沟的一项地震调查表明，在类似7级的M级地震重现区附近，有一大片海山正在俯冲。1982年7级地震期间观测到的地震活动和破裂传播模式都表明，海山上的板间耦合作用很弱。海山前存在一个大的破裂带和小的滑移带。它的北界可以由多座俯冲的海山的踪迹来确定。虽然俯冲的海山本身不能确定破裂区域，但其宽度可能会受到海山宽度的影响。
Subducting seamounts are thought to increase the normal stress between subducting and overriding plates. However, recent seismic surveys and laboratory experiments suggest that interplate coupling is weak. A seismic survey in the Japan Trench shows that a large seamount is being subducted near a region of repeating earthquakes of magnitude M similar to 7. Both observed seismicity and the pattern of rupture propagation during the 1982 M 7.0 event imply that interplate coupling was weak over the seamount. A large rupture area with small slip occurred in front of the seamount. Its northern bound could be determined by a trace of multiple subducted seamounts. Whereas a subducted seamount itself may not define the rupture area, its width may be influenced by that of the seamount.