嘉南地區為一鬆軟的沖積平原，且地震活動頻繁。過去百年來，嘉南地區曾發生過多次重大地震災害。最近發生的921 集集地震以及1022 嘉義地震都在嘉南地區造成嚴重災害，一般認為是震波經過沖積層時會有放大的作用。嘉南地區人口稠密，對於該地區進行詳細的地球物理探勘是刻不容緩的，其結果可供地震定位、發震機制、震波放大等研究使用。除了去年度計畫對於嘉南地區的調查研究外，今年度的計畫開始針對埔里盆地進行重力相關測勘工作。本計畫將收集中國石油公司在嘉南地區及南投地區的重力測量資料，並在資料較少的區域增加重力測點，繪製這兩個地區之布蓋重力、剩餘重力、及微分重力圖；並配合震測剖面結果模擬研究區之二維及三維密度構造。 ; The Chianan area is a typical plain and then the sediments and sedimentary rocks in the plain are extremely soft. It is well accepted that some earthquake damages at the Chianan area generated by both of the 921 Chi-Chi earthquake and the 1022 Chiayi earthquake are primarily associated with the basin effect of the seismic wave amplification. Therefore, it is one of the very urgent works to do geophysical exploration at the Chianan area, due to the extremely high-density population. This result will provide basic information for locating earthquakes, determining focal mechanisms, studying seismic amplifications and so on. In addition, the Puli basin will be investigated simultaneously. In this study, we will combine gravity data collected by the CPC with some new survey in the both areas where the gravity data are absence to make new maps including the Bouguer anomaly map, residual anomaly map and derivative anomaly map. Finally, the 2-D and 3-D density structures will be obtained from those anomaly maps as well as seismic profiles from other studies. ; 研究期間 9708 ~ 9807
