RESEARCH INTO THE MULTIFRACTAL OF EARTHQUAKE SPATIAL-DISTRIBUTION

The spectra D(q) of the Henon map are calculated and analyzed using the extended G-P method. The key problems (such as the scaling range determination, data sample selection and the calculation method) are also discussed. Results show that the scaling radius, r, should be less than about 1/3 of the diameter of the research object (e.g., the earthquake region) for reducing the boundary effect and a sample volume of 500 may be sufficient for the small absolute of the q value. We also calculate and study the whole multifractal spectra D(q) of available seismic data; for example, the catalogue of earthquakes which have the occurred in Tangshan region, North China. The results show that there is a multifractal in the data, and that the D(q) value showed a remarkable variation with time before the large Tangshan earthquake of July, 1976.