M8.1 - EAST OF THE KURIL ISLANDS

Tectonic Summary

The Kuril Islands earthquake of January 13, 2007, occurred as normal-faulting in the Pacific plate near the boundary between the Pacific plate and the Okhotsk plate. In the region of the earthquake's epicenter, the Pacific plate moves northwest with respect to the Okhotsk plate with a velocity of about 90 mm/year. The Pacific plate subducts beneath the Okhotsk plate at the Kuril Trench and becomes progressively deeper to the northwest, remaining seismically active to a depth of 680 km. The January 13 earthquake occurred approximately 95 km ESE of an M8.3 earthquake that occurred on November 15, 2006. The November 15 earthquake is the largest earthquake to have occurred in the central Kuril Islands since the early 20th century. A central Kuril Islands earthquake in 1915 is estimated to have had a magnitude of about 8. The central Kuril Islands commonly experiences one or more shocks of magnitude 6 or greater in a decade. To the southwest, the southern Kuril Islands chain experienced a magnitude 8.5 earthquake in 1963. To the northeast, a magnitude 9 earthquake occurred offshore of Kamchatka in 1952.

Earthquake Summary Poster: Comparison of the Kuril Islands Earthquakes of 15 November 2006 and 13 January 2007