Abstract:

Based on the data in seismic catalog , the characteristic of unequal time periods in different areas is considered in the spatialization of earthquake frequency. "Value of grid nodes density calculating of earthquake epicenter distribution group by magnitude" method is improved to spatialize point data to grids which describe earthquake frequency from the seismic catalog with the assistance of GIS spatial analysis methods. Furthermore, according to the relationship between earthquake magnitude and intensity and the model of elliptical attenuation of earthquake intensity, spatial interpolation method, approximation method and approaching method are chosen to obtain grids which describe the average seismic intensity in China. The results of earthquake frequency distribution in China indicates that the frequency of earthquake magnitude above 3 in western China is higher than that of the eastern China bounded by a strip which consists of Shanxi, Ningxia, Gansu, Sichuan and Yunnan provinces. It is concluded from the results of seismic intensity distribution in China that Gansu, Shanxi, Ningxia, Hebei, Sichuan and Yunnan provinces, which are located in seismic belts, are likely to encounter earthquakes that often cause higher intensity.

Key words: earthquake frequency, GIS, intensity, seismic catalog, spatialization