气候变化领域集成服务门户(CCPortal): Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago

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DOI	10.1016/j.tecto.2021.228757
	Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago
	Kuwahara Y.; Choi J.-H.; Cheon Y.; Imanishi K.
发表日期	2021
ISSN	00401951
卷号	804
英文摘要	We re-evaluate the stress state across the Korean Peninsula by analyzing the stress tensor inversion results, strike–rake relationships, and faulting-type indicator–magnitude relationships of published earthquake focal mechanism data. Previous studies have shown that the stress state is characterized by a strike-slip faulting stress regime with ENE–WSW maximum compression, NNW–SSE minimum compression, and vertical intermediate stress. The differential stress magnitudes are estimated to be on the order of 100 MPa under the assumption of the strong-fault earthquake with a high Coulomb friction coefficient of 0.85. Conversely, other studies have shown that the weak-fault model is applicable across the Japanese Archipelago, where the differential stress level is only a few tens of MPa. We, therefore, review previous studies, evaluate the focal mechanism data across the Korean Peninsula, and infer the absolute stress level. Our comparison of the geological and tectonic histories of the Korean Peninsula and Japanese Archipelago suggests that the NNW–SSE tensional stresses in the Korean Peninsula are caused by slab rollback of the Philippine Sea Plate at around 5 Ma, west of Kyushu Island, southwestern Japan. We also find that the earthquake faulting types across the Korean Peninsula are closely related to their fault strikes, confirming a spatially uniform distribution of the strike-slip stress regime with nearly equal tensional and compressional tectonic stresses. However, this situation leads to the apparent paradox of strike-dependent fault strength. We eliminate this paradox by proposing a model whereby reverse- and normal-faulting events are caused by local stress heterogeneities around the edges of strike-slip faults under a uniform low-strength strike-slip stress state for all faulting types. We also highlight the usefulness of strike–rake and faulting-type indicator–magnitude diagrams in considering stress states. © 2021 Elsevier B.V.
关键词	Crustal stress Focal mechanism Japanese Archipelago Korean Peninsula Weak fault
英文关键词	Earthquakes; Friction; Strike-slip faults; Compressional tectonics; Coulomb friction coefficient; Differential stress; Earthquake focal mechanisms; Intermediate stress; Stress tensor inversions; Strike slip faulting; Uniform distribution; Fault slips; earthquake event; fault zone; faulting; focal mechanism; moment tensor; normal fault; stress analysis; strike-slip fault; Japan; Korea
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208000
作者单位	Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, South Korea; Geological Survey of Japan, AIST, Tsukuba, 305-8567, Japan
推荐引用方式 GB/T 7714	Kuwahara Y.,Choi J.-H.,Cheon Y.,et al. Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago[J],2021,804.
APA	Kuwahara Y.,Choi J.-H.,Cheon Y.,&Imanishi K..(2021).Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago.Tectonophysics,804.
MLA	Kuwahara Y.,et al."Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago".Tectonophysics 804(2021).