THE RESEARCH ON DETERMINING THE ANNUAL OCCURRENCE RATES OF POTENTIAL SEISMIC SOURCE AREAS

To actually reflect the seismic temporal-spatial inhomogeneity of intracontinental strong earthquakes of North China in seismic hazard analysis, several seismological and geological characteristics have been selected and quantized to describe the seismicity features in time and space of every magnitude interval with the thought of dividing the interesting magnitude range into several intervals and using of the spatial probability distribution function. A component analysis method with orthogonal transformation is introduced to avoid the repeated use of the same element and the subjective effects in determining the annual occurrence rates. By passing synthetic fuzzy judgement on the nonintercorrelated new characteristics, the annual occurrence rates of every magnitude interval of each potential source area are obtained associated with the adjustments of earthquake reducing process after the occurrence of M>7 quake. An intensity map of the Beijing-Tianjin-Tangshan-Zhangjiakou area is calculated as an example which shows a close coincidence with the seismic temporal-spatial inhomogeneity of North China.