New data on natural strains within the area of preparation for strong earthquake.
The model of the earthquake source
© Yu.L. Rebetskiy
Problems are being considered, which should be attributed to the development of physical bases of earthquake mechanics. Results of restoration of parameters of the stress state have been presented obtained for a set of seismically active areas of the Earth's crust in case of application of the method of cataclastic analysis of slip faults. Analysis of regularity of strained state within the areas of preparation for strong earthquakes is given. It has been shown on examples of earthquakes of Tokachi-Oki, 2003 and Sumatra-Andamanian, 2004 that distribution of effective isotropic pressure and maximum shear stresses within such areas has considerable heterogeneities. Similar regularity is in agreement with theoretical analysis, which determines effectiveness of brittle destruction within the areas of medium level of isotropic pressure and corresponding predominance of rupture development from the area of high isotropic pressure to the areas of its smaller values. Based on regularities revealed grounding of a new model is given for producing the earthquake sourse.