Relocating the 2011 Tohoku-oki earthquakes (M 6.0-9.0)
Relocating the 2011 Tohoku-oki earthquakes (M 6.0-9.0)
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重新定位 2011 年东北冲地震(震级 6.0 至 9.0)
DOI:
10.1016/j.tecto.2012.10.019
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发表时间:
2013-02-26
期刊:
影响因子:
2.9
通讯作者:
Zhao, Dapeng
中科院分区:
文献类型:
--
作者:
Huang, Zhouchuan;Zhao, Dapeng
The great Tohoku-oki earthquake (Mw 9.0) on 11 March 2011 was accompanied by nearly 100 large foreshocks and aftershocks (M >= 6.0) in the Northeast Japan forearc. In this study we relocated 77 of these large events using three different velocity models. An updated three-dimensional velocity model significantly reduced the travel-time residuals in the earthquake relocation. We found that the large thrust earthquakes are generally located in or around high-velocity patches, suggesting that the generation of the large thrust earthquakes is controlled by structural heterogeneities in the megathrust zone. The high-velocity patches may represent asperities in the megathrust zone where the subducting Pacific plate and the overriding Okhotsk plate may be coupled strongly. Many non-thrust earthquakes occurred in the crust of the overriding Okhotsk plate, indicating that the stress field there has been changed by the Tohoku-oki mainshock. The present results may improve our understanding of the subduction dynamics and seismotectonics of the Northeast Japan arc. (C) 2012 Elsevier B.V. All rights reserved.