A SEISMIC GAP ON THE XIANSHUIHE FAULT, SICHUAN PROVINCE

In this paper, based on the distribution of epicenters of earthquakes of magnitudes M 5 and the magistoseismic areas of earthquakes of M 6(1/2) occurred during the years from 1900 to 1981 as well as the distribution of the fracture zones of those earthquakes and the aftershocks of the major earthquakes occurred during the years from 1967 to 1981, it has been inferred that between Daofu and Gianning along the Xianshuihe Fault, a segment of seismic quiescence exists. In analysing the seismic activity of weak earthquakes of this area and the data of crustal deformation measurements, it does not seem to be a creeping portion of the fault. Therefore, it may be considered that this is a seismic gap, the first kind of Mogi, at least.According to statistical estimation, the maximum magnitude of the coming earthquake may be possibly 7(1/2).