DOI: 10.1016/j.tecto.2021.228757
论文题名: Dependence of earthquake faulting type on fault strike across the Korean Peninsula: Evidence for weak faults and comparison with the Japanese Archipelago
作者: Kuwahara Y. ; Choi J.-H. ; Cheon Y. ; Imanishi K.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 804 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170833
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
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]. Tectonophysics,2021-01-01,804