Institute of Nature and Environmental Technology Kanazawa University
Abstract
In the sea area off the west coast of the Noto Peninsula, there are faults and flexures that have been formed since the Tertiary Period. It is also the area in which the magnitude 6.9 Noto Hanto earthquake occurred on March 25th 2007. Many acoustic surveys have been carried out and have revealed the vertical cross-sections of subsurface sedimentary structures in this area. In this study, we compiled the boundary depths of the sedimentary structures, together with the distribution of faults and flexures, and created a three-dimensional (3D) depth distribution of the boundaries of the subsurface geological structures formed since the Tertiary Period in this area. The obtained 3D depth distribution of the boundaries illuminates the distribution of the flexure structure in the sea area off the city of Hakui at each boundary. We recognized that the boundary depths change steeply for the Quaternary Period reverse faults that lie relatively close to the coast, while little for the faults far from the coast
