Geodetic constraint on the slip distribution of the 2006 Central Kuril earthquake

Abstract

We have investigated the slip distribution of the 15 November 2006 Central Kuril earthquake off Simushir Island using continuous GPS data. A dense GPS network on Hokkaido Island, northern Japan, and Sakhalin Island detected coseismic horizontal displacements of ∼9 mm despite large epicentral distances of about 900-1200 km. Eastward displacements at the sites decrease to the south, and this spatial distribution feature constrains the slip on the three subfaults. Our data suggest that little slip has occurred in the southern and northern parts, but that a 6-m slip has occurred in the center of the focal region. This interpretation fits well with the detailed slip distribution inferred from teleseismic waveform inversions. The total seismic moment, 2.8 × 1021 N m, is approximately the value indicated using by the Global CMT solution. Our result implies that there remains a seismic gap between this event and the 1952 great Kamchatkan earthquake that is large enough for an M > 8 earthquake. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences; TERRAPUB.