六甲斷層古地震暨構造模擬研究

Based on historical earthquake record, catastrophic earthquake with a magnitude of greater than 7 hits the western Taiwan roughly every thirty years. As for earthquakes with a magnitude of 6, the reoccurrence time is even shorter. In twentieth century, there was at least 10 earthquakes with a magnitude of equal or greater than 6 occurring in Chia-Tainan region, south-western Taiwan, including 2 earthquakes with a magnitude of greater than 7. However, the existence of LiuChia active fault, commonly considered as the western deformation front inthis region, is very disputable. Due to its importance in earthquake hazard assessment, clarification and deeper understanding for LiuChia fault is of great urgency. There is dramatic difference in the surface deformation resulted from faulting or folding Therefore, this study proposes to drill boreholes in the hangwall in the location where a former study claimed one of their boreholes penetrated the fault plane, dig a trench for paleoearthquake study and perform structural simulations. The results are expected to settle down the dispute, attain the reoccurrence interval of the LiuChia fault, its fault dip anlge, and cumulative fault reverse slip.