THE PLATE SUBDUCTION UNDER KAMCHATKA: «SEISMIC » SPEED, SLOW EVENTS, DEFORMATION VELOCITY

• Main Authors: E. I. Gordeev, V. M. Pavlov, V. E. Levin, V. F. Bakhtiarov
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Gusev; Pacific; Kamchatka
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.1440; http://kiska.giseis.alaska.edu/kasp/kasp04/abstracts/gordeev.pdf

Some results concerning subduction process of the Pacific plate under Kamchatka and related phenomena are presented. Estimates of seismic component of the velocity V of the subducting plate by CMT mechanisms and series of great earthquake in Kamchatka are obtained. The interface boundary between subducting plate and Kamchatka (the continental plate) at depths 30-70 km is supposed to be a rectangle with strike 37°+180 ° and dip angle DIP. The rectangle location and DIP value are determined from analysis of CMT of earthquakes (1976-2003 yy) with Mw>5.5. The rectangle location is determined by CMT hypocenters cloud (DIP=25°). It turns out that the planes of CMT dipping under Kamchatka have the same dip angle 25°. For the velocity V value we have estimates: in south zone (south of c. Shipunsky): V=0.9 cm/y; in central zone (from c. Shipunsky to c. Kronotsky): V=1.4 cm/y. We have information about great Kamchatka earthquakes since 1737 year. In south zone there are 3 earthquakes with Mw>8.5 (moment magnitude estimates by (Gusev, Shumilina, 2004)). In central zone there are 2 earthquakes.