The Characteristics of Surface Ruptures and Landslides in the Chi-Chi Earthquake of September 21th, 1999

The Chi-Chi, Taiwan Earthquake provides an exceptional opportunity to study surface rupture of an earthquake fault. Detailed maps of the lateral distribution of fracturing adjacent to main traces show the different amount of offset and the slip rational in vertical to lateral. The maximum value of offset is up to 10 meters and it is much higher than documented in past studies of earthquake fault. Earthquake faulting also triggers the different types of landslide hazards, and these high-risk areas of landslides hazard should be treated immediately and carefully. Based on investigations on Nantou area, we observed lots of landslides located in tableland that composed by red soil around Puli basin. Lots of landslide debris filled ravines, they pose a continuing hazard from remobilization and flow during future intense, prolonged rainfall.