Fault model of the 2007 Noto Hanto earthquake estimated from PALSAR radar interferometry and GPS data

The 2007 Noto Hanto earthquake (M_w 6.6) is the first major earthquake in inland Japan since the launch of the Japanese ALOS satellite. Interferometric synthetic aperture radar successfully mapped the coseismic displacements from both ascending and descending orbits in and around the earthquake epicentral region. The line-of-sight displacements toward the satellite from the ascending and descending orbits amount to about 50 and 20 cm, respectively. The interferograms as well as the GPS data of the GEONET network are inverted in order to determine the slip distribution on the source fault. The dip and strike angles of the preferred model are 48° and N51°E, respectively, and its fault slip area reaches the seafloor. The dip angle is not well constrained in our tested range between 40° and 60°. The dominant slip area is located just above the hypocenter, at depths between 4 and 10 km. Many aftershocks seem to have occurred on and around the area of dominant slip.