The 1999 Chi-Chi (Taiwan) Earthquake: Earthquake Fault and Strong Motions

We report the results of a field survey on the Chelungpu surface rupture zone and building damage as well as the analysis of strong motions of the Chi-Chi (Taiwan) earthquake. Damage due to this earthquake is classified into the three main types: (1) damage due to large displacements along the surface rupture zone, (2) widespread spots or patches of demolished areas that might be attributed to localized strong ground motions, and (3) damage in remote regions as in Taipei caused by anomalous amplifications of strong motions. Damage tends to be localized in areas of several tens to hundreds of meters long and is characterized by intermittent arrivals of intense shaking. The surface rupture occurred mainly along the active Chelungpu fault. We also found some evidence that large buildings might have affected the rupture process on the surface. Manuscript received 31 July 2000.