Geological–Geophysical Model of Northeastern Kamchatka and Regional Seismic Activity in 2013

Abstract

We analyze the results of geophysical studies of the crust and upper mantle which were carried out in 2000–2013 in the Kamchatka isthmus area. The obtained data reveal obduction (thrusting of suboceanic lithosphere upon the margin of the continental one) in the study area, indicating potentially high seismic hazard in the entire frontal zone of obduction. A comprehensive geological–geophysical model is developed along the profile that passes between Ossora and Tilichiki settlements, along the obduction front. In 2013, strong seismic activation was recorded in the northeastern part of the region; the Il’pyr earthquake was the first in the series. The comparison between modeling results and the real seismic lineament shows that tectonic stresses accumulate on the faults between lithospheric blocks and then release in the form of seismic events, as was recorded in the obduction zone between Ossora and Tilichiki settlements in March–May 2013.