| Geological Investigation of Chelungpu Fault before and after Chi-Chi Earthquake
集集地震前後車籠埔斷層調查
The Chi-Chi earthquake (ML7.3) occurred in central Taiwan on Sept. 21, 1999 at 1:47 a.m. The epicenter lied in Chi-Chi township, Nantou county. It was the strongest earthquake recorded since the Hshinchu-Taichung earthquake, 1935, in central Taiwan. The 100 kilometer-long surface rupture resulted along the juncture between foothills and Taichung basin from Zhuolan township in Miaoli county to Tongtou bridge in Nantou county. “Investigation on Chelungpu Fault”, which the Taiwan Provincial Government commissioned Central Geological Survey (CGS) to survey the capability for Taichung MRT system in 1997, has already been finished the part from Taiping to the north bank of Choushui river, and the site at the surface rupture of Chi-Chi earthquake turned out to fit the location of Chelungpu fault. In the aftermath of this earthquake, the CGS spares no efforts to investigate and record the disaster, inclusive of the crustal deformation observation , Global Positioning System (GPS) and Precise Leveling.
1999年9月21日凌晨1時47分中部地區發生規模7.3的大地震，震央位於中部南投集集地區，為1935年新竹-台中大地震以來，最為嚴重的地震災害，地表破裂北從苗栗卓蘭起，沿麓山帶與台中盆地的交接處破裂，向南延伸至南投南邊的桶頭橋，破裂長度約100公里。在1997年地質調查所受省府委託為台中捷運而進行的「車籠埔斷層調查研究」，其中已完成太平至濁水溪北岸的調查，集集地震地表破裂跡與當初調查的車籠埔斷層位置相當吻合。地震後中央地質調查所積極投入災後地質調查，紀錄災害狀況。之後地質調查所投入相當多的人力與物力持續進行中部地區的地殼變形觀測，包括GPS與精密水準測量。 |
