Present-day stress state in southeast Korea with an emphasis on effects of regional-scale faults
Present-day stress tensor is characterized in southeastern Korean Peninsula using shallow geotechnical in situ stress data to understand the regional contemporary stress state and its relationship to the population of faults. The in situ stress data show an ENE-WSW to NE-SW maximum compression direction, which is in accord with the contemporary earthquake focal mechanism solutions, as well as the first order pattern of tectonic stress direction in the eastern Eurasian plate. The current stress tensor exhibits a heterogeneity in its orientations and magnitudes, possibly caused by the influence of faults. The horizontal principal stresses normalized by vertical stress vary spatially. The magnitude of stress field appears to be inversely correlated with the density of regional scale faults, suggesting that a stress relief due to faulting may be one of the major factors that contribute to low stress magnitudes. As a way to confirm the inference, we examine the attitudes of Quaternary faults with respect to the current stress field. A majority of the faults are oriented in the optimal directions for slip, as indicated by the overall high ratios of shear to normal stress acting on fault planes for the given stress condition, which implies that they might sustain the current stress field.
C. Chang T.S. Kang
Chungnam National University, Daejeon, South Korea Pukyong National University, Busan, South Korea
国际会议
The Fifth International Symposium on In-situ Rock Stress(第五届国际岩石应力研讨会)
北京
英文
701-705
2010-08-25（万方平台首次上网日期，不代表论文的发表时间）