Active faults and large earthquakes around the Japan Trench

Abstract

We investigated feature of active structures around Japan Trench based on 3D anaglyph images. An extensive reverse fault over 500-km long cuts the landward slope of the trench. This active fault has originated very large earthquakes. The 2011 off the Pacific of Tohoku Earthquake was the same as the previous characteristic earthquakes. It is essential to examine submarine active faults in order to make an accurate estimate of future large earthquake. According to the relationship between the hipocentral regions of historical earthquakes and submarine active faults, there are two large seismic gaps along Japan Trench.