RESEARCH INTO THE MULTIFRACTAL OF EARTHQUAKE SPATIAL-DISTRIBUTION

The spectra D(q) of the Henon map are calculated and analyzed using th e extended G-P method. The key problems (such as the scaling range det ermination, data sample selection and the calculation method) are also discussed. Results show that the scaling radius, r, should be less th an about 1/3 of the diameter of the research object (e.g., the earthqu ake region) for reducing the boundary effect and a sample volume of 50 0 may be sufficient for the small absolute of the q value. We also cal culate and study the whole multifractal spectra D(q) of available seis mic data; for example, the catalogue of earthquakes which have the occ urred in Tangshan region, North China. The results show that there is a multifractal in the data, and that the D(q) value showed a remarkabl e variation with time before the large Tangshan earthquake of July, 19 76.