The Great 2006 and 2007 Kuril Earthquakes, Forearc Segmentation and Seismic Activity of the Central Kuril Islands Region

摘要: We present a structural study of the Central Kuril Islands forearc region, where great megathrust tsunamigenic earthquake (M w 8.3) occurred on November 15, 2006. Based new bathymetry and seismic profiles obtained during two research cruises R/V Akademik Lavrentiev in 2005 2006, ten crustal segments with along-arc length ranging from 30 to 100 km, separated by NS– NW–trending transcurrent faults were identified within region. The may serve as barriers impeding stress transfer between neighboring segments, so that accumulated separate is usually released earthquakes moderate-to-strong magnitudes. However, 2006 ruptured seven probably following 226-year gap since last 1780. geographic extent rupture zones, aftershock areas clusters correlate well using geophysical data. segmented structure we consider discuss three scenarios occurrence this area. Although margin segmented, suggest could occupy entire total about 500 km. In such case, magnitude M might exceed 8.5, an event generate tsunami waves significantly exceeding height those produced 2006–2007 earthquakes.