Author(s): Ma Zongjin； Li Xianzhi（Institute of Geology, SSB，Beijing 100029）（Center for Analysis and Prediction，SSB，Beijing 100029）
Pages: 127-136
Year: 1994 Issue:  2
Journal: Seismology and Geology
Keyword:  ：Global seismic zones; Orientational migration; Geodynamic interpretation;
Abstract: Based on the analysis of the orientational migration of 184 earthquakes of Ms≥73／4 orgreater along 6 seismic zones which are of a global scale，we found the phenomenom of global ori-entational migration of earthquakes。Generally the migrations take place from the western to theeastern，with their velocities ranging from 700km／a to 140km／a.The global orientational migra-tion of major earthquakes can be interpreted by various geedynamic processes such as the P waveshaped oscillation propagation of the movement of the upper mantle material from the western tothe eastern caused by intermittent extensional break along the Alantic ridge.It can also be inter-preted by eastward propagation of strain wave caused by the sequent SW-NE compression on theEurasia seismic zone from the Africa，Arabia，and India plates；and the NW and NE orientatedoblique compression of the oceanic plate on the both sides of the Pacific ridge.