抄録
Theoretical source studies can be classified into three categories, i.e., applications of crack theory to source processes, studies of constitutive laws, and fractal approaches. The seismic source process was studied using dislocation theory in the 1960's. In the 1970's it was replaced by crack theory. In the 1980's, studies of the constitutive laws that control faulting processes and studies of the fractal structure of earthquake phenomena have appeared.
