Influence of crustal inhomogeneity on seismicity in North China

North China is one of the regions with most frequent earthquake disaster in the China mainland.The spatial distribution of major earthquakes may be caused by regional crustal inhomogeneity.In order to discuss the relationship between crustal inhomogeneity and seismicity,we construct a three-dimensional finite element model in North China,and simulate regional crustal movement field and stress field.Parameters of shear wave splitting were used as new constraints in the model.The primary results show that the dynamic boundary condition controls crustal motion pattern in North China.The lateral and vertical crustal inhomogeneities both affect local deformation.The difference between seismicity in western North China and in eastern North China is controlled by lateral crustal inhomogeneity.The crustal material in eastern North China is relatively weak,which results in high elastic strain energy accumulation, and more frequent seismicity.The crustal material in west North China is relatively hard,which causes relatively lower elastic strain energy accumulation,and less frequent seismicity.