Earthquake Research Institute, the University of Tokyo
Earthquake Research Institute, the University of Tokyo
JGI, Inc.
Earthquake Research Institute, the University of Tokyo
Earthquake Research Institute, the University of Tokyo
Earthquake Research Institute, the University of Tokyo
Iwate University
JGI, Inc.
Earthquake Research Institute, the University of Tokyo
登録日
2013-02-05
雑誌名
Earth, planets and space
巻
63
号
8
ページ
949 - 954
発行年
2011-01-01
ISSN
1343-8832
Abstract
The 2008 Iwate-Miyagi Nairiku Earthquake (Mj 7.2) occurred on June 14, 2008, at the eastern flank of the Ou backbone range, in the central part of northern Honshu, Japan. In the northern part of the focal area, seismic reflection/refraction experiments conducted in 2006 and 2007 revealed a series of west-dipping faults. To investigate the relation between these faults and aftershocks, we conducted a high-density seismic array observation across the northern focal area. The arrival times of earthquakes were used in a joint inversion for earthquake locations and velocity structure. The Vp structure shows tilted blocks and the block boundaries coincide with the revealed west-dipping faults. These faults were interpreted to have formed during the Miocene extension. The aftershock distribution shows a concentration on a plane dipping westward approximately 40° beneath the eastern margin of the Ou backbone range. The zone of aftershock concentration can be correlated to the known range-bounding fault inferred from seismic profiling and does not coincide with the known active reverse fault (Dedana fault). These results indicate the significance of the potential source fault located along the boundary of the Ou backbone range.
出版者
Terra Scientific Pub. Co
権利
Copyright c 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.
Precise aftershock distribution and crustal structure in and around the northern focal area of the 2008 Iwate-Miyagi Nairiku Earthquake
eps-v63n8p949-954.pdf
(3.5MB)
