The Detection of Active Faults on Taiwan Using Shallow Reflection Seismics

The purpose of this study is to detect some active faults in western Taiwan using the newly developed shallow seismic reflection method.Most of these faults are in urban areas or close to the populous regions, hence, it is important with respect to earthquake hazard mitigation.The position, fracture attitude, faulting mechanism and even activity of the fault are under investigation.The revealed fault images from some s.eismic •sections are so sharp that many details can be measured.It is found that every fault has its own charac teristics.They all behave differently.The following conclusions are obtained: TAO, Vol.5, No.2, June 1994 (5) Hsinhua fault (1946 earthquake) has developing fracture type.1\vo frac ture zones were found, which are separated more toward the east.A large disturbance occurred within a 60 m range where the two fracture zones came together in the west, The reflection signals in this 60 m zone were totally •1ost due to elimination of layering by mass mixture on the fault.Outside the fault zone, however, the layer is quite flat and free of disturbance.