Abstract The January 23, 2018 M7.9 earthquake ruptured conjugate set of strike-slip faults in the outer rise of the Alaska subduction zone, southeast of Kodiak Island. The complex nature of this earthquake is evident from the earthquake focal mechanism and aftershock relocation patterns which revealed rupture of multiple north-south and east-west trending conjugate fault planes. Here, we suggest that this earthquake occurred as a result of two different modes of interaction process. The stress triggering process reveals (i) the co-seismic and post-seismic deformation of the M9.2 1964 Alaska megathrust earthquake increased Coulomb failure stress of ∼10 kPa and ∼0.05 kPa respectively in the 2018 Kodiak earthquake source region, and (ii) the overall deformation is being accommodated in the outer rise region due to slip partitioning resulting from the oblique convergence between the Pacific and North American plates along the Alaska Aleutian megathrust.

中文翻译：

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2018 年 1 月 23 日，阿拉斯加 M7.9 科迪亚克地震：外上升区滑动分隔的结果

摘要 2018 年 1 月 23 日 M7.9 地震破坏了科迪亚克岛东南部阿拉斯加俯冲带外隆起的走滑断层共轭组。本次地震的复杂性从震源机制和余震重定位模式中可见一斑，该模式揭示了多个南北向和东西向共轭断层面的破裂。在这里，我们认为这次地震的发生是两种不同模式的相互作用过程的结果。应力触发过程揭示了（i）M9.2 1964年阿拉斯加特大地震的同震和震后变形使2018年科迪亚克震源区的库仑破坏应力分别增加了~10 kPa和~0.05 kPa，