3D-analysis of the Japanese islands and adjacent aquatorials lithosphere seismicity

In the article, the author considers 3D models of distributions of earthquakes hypocenters and magnitudes in the crust and upper mantle of the Japanese islands and surrounding water areas. Vertical and horizontal variations of the earthquake magnitudes are described. It is revealed the new features of the tectonosphere layering of the Japan Sea region and the Pacific-Japanese seismic-focal zone structure. The constructed models assume much more complex mechanisms of the Pacific plate collision with the Japanese island arch in comparison with the standard models of subduction. The linear zone of concentration of the NE strike earthquake hypocenters is located on the oceanic coast of the Hokkaido Island and in the southern part of the Kuril island arch. On the Japanese segment (Honshu Island), linear zones of abnormal seismicity have the NE strike. Their mutual arrangement and the trends of the earthquake magnitude distributions show the signs of the left shift on the border of the Pacific and Okhotsk lithospheric plates. Lateral variations of the earthquake magnitudes in the crust and upper mantle of the Japan Sea region are characterized by opposite trends.