Reconstruction of the tectonic stress field before and after Japan earthquake 11 march 2011

Purpose. The purpose of the research is to study the features of the tectonic stress field before and after the 2011 Japan earthquake. Methodology. The reconstruction of the tectonic stress field is carried out on the basis of cataclastic analysis method of earthquake focal mechanism. The method allows us to define the tectonic stress tensor parameters and increments of quasi-plastic deformation. Results. The detailed studies of the tectonic stress field are performed on the basis of cataclastic analysis method of earthquake focal mechanism within the coast of Honshu Island before and after the 2011 Japan earthquake. New data on the tectonic stress field features is obtained for the study region: the orientation of the principal stress axes, distribution of Lode – Nadai coefficient (stress ratio) and effective confining pressure. The geodynamic zoning of the study region is carried out. Originality. New results on the regional modern tectonic stress field within the east coast of Honshu Island, Japan are obtained. The comparison between the stress states before and after the 2011 mega-earthquake, Mw = 9.1 is carried out. Practical significance. The results of the research can be the basis for seismic zoning maps of tectonically active areas of the earth's crust, for a more detailed study and prediction of seismicity features in the study region in time and space.