Tsunami waveform analyses of the 2006 underthrust and 2007 outer-rise Kurile earthquakes

Abstract. The 2006 large interplate Kurile earthquake proved that the entire plate interface of the Kurile-Kamchatka subduction zone was strongly coupled from Hokkaido, Japan, to Kamchatka, Russia. The seismic moment of the 2006 Kurile earthquake estimated from ten tsunami waveforms is 3.1×10²¹ Nm (M_w=8.3). This estimate is consistent with the seismic moment estimated from the seismological data in the Global CMT catalog. The computed tsunami propagation indicates that scattering of the tsunami waves occurred at the shallow region near the Emperor Ridge. The computed tsunami propagation also indicates that large later tsunami waves observed at Crescent City is caused by the shallow region along the Mendocino Fracture Zone. The seismic moment of the 2007 outer-rise Kurile earthquake estimated from tsunami waveforms is 1.0×10²¹ Nm (M_w=8.0). This estimate is also consistent with the seismic moment in the Global CMT catalog.