Tracing The Mohorovicic Discontinuity along The North-Eastern Japanese Islands Arcs

Abstract

The gravity anomaly distribution in and around Japan was used together with the explosion seismic data in order to trace the Mohorovicic discontinuity along the northeastern Japanese arcs. The present paper represents the application of Talwani's method along several profiles-chosen to be perpendicular to the Pacific trench axisassuming that the crust consists of a single homogeneous layer and the density contrast Δρ =0.38 g/cm³ between the crust and upper mantle. A contour map is drawn using the calculated depths of Mohorovicic discontinuity. It shows that the crustal thickness varies between 24-31 km, 28-32 km, 30-34 km and between 33-35 km in Hokkaido, Tohoku, Kanto and Chubu areas respectively.