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Crustal deformation and a preliminary fault model of the 2007 Chuetsu-oki earthquake observed by GPS, InSAR, and leveling
Earth, Planets and Space volume 60, pages1093–1098(2008)
The 2007 Chuetsu-oki earthquake occurred just west off the coast of Kashiwazaki in Niigata Prefecture, Central Japan on July 16, 2007. The permanent GPS network (GEONET) clarifies the coseismic displacement as a thrust faulting whose compressional axis lies in the NW-SE direction. Interferometric analysis of synthetic aperture radar (SAR) images acquired by “Daichi” satellite (ALOS) maps a detailed spatial pattern of the displacement toward the satellite for both ascending and descending orbits. Peak-to-peak displacement reaches approximately 400 mm in the descending orbit interferometric (In)SAR data. Repeated precise leveling shows uplift near the northeast part of the aftershock area and subsidence near the southwestern part. We construct a preliminary fault model by inverting the observed deformation. The preferred model consists of two segments of rectangular faults whose moment magnitude is 6.7 in total. From only the used geodetic data on land, it is difficult to determine which plane in two conjugate planes of the focal solution was ruptured. It is important to consider the effect of a heterogeneous medium and variable slip on the faults as well as other geophysical data to determine the fault model with confidence.
Aoki, S., M. Nishi, K. Nakamura, T. Hashimoto, S. Yoshikawa, and H. M. Ito, Multi-planar structures in the aftershocks distribution of the Mid Niigata prefecture Earthquake in 2004, Earth Planets Space, 57, 411–416, 2005.
Ikeda, Y., The origin and mechanism of active folding in Japan, Active Fault Research, 67–70, 2002 (in Japanese with English abstract).
Kato, A., S. Sakai, E. Kurashimo, T. Igarashi, T. Iidaka, N. Hirata, T. Iwasaki, T. Kanazawa, and Group for the aftershock observations of the 2007 Niigataken Chuetsu-oki Earthquake, Imaging heterogeneous velocity structures and complex aftershock distributions in the source region of the 2007 Niigataken Chuetsu-oki Earthquake by a dense seismic observation, Earth Planets Space, 60, this issue, 1111–1116, 2008.
Matsu”ura, M. and Y. Hasegawa, A maximum likelihood approach to nonlinear inversion under constraints, Phys. Earth Planet. Inter., 47, 179–187, 1987.
Nakajima, J. and A. Hasegawa, Deep crustal structure along the Niigata-Kobe Tectonic Zone, Japan: Its origin and segmentation, Earth Planets Space, 59, e5–e8, 2007.
Nishimura, T., M. Tobita, H. Yarai, T. Amagai, M. Fujiwara, H. Une, and M. Koarai, Episodic growth of fault-related fold in northern Japan observed by SAR interferometry, Geophys. Res. Lett., 35, L13301, doi:10.1029/2008GL034337, 2008.
Okada, Y., Surface deformation due to shear and tensile faults in a halfspace, Bull. Seismol. Soc. Am., 75, 1135–1154, 1985.
Research Group for Active Faults of Japan, Active Faults in Japan: sheet maps and inventories (Revised ed.), 437 pp., University of Tokyo Press, Tokyo, 1991 (in Japanese).
Sagiya, T., A decade of GEONET: 1994–2003—The continuous GPS observation in Japan and its impact on earthquake studies, Earth Planets Space, 56, 39–41, 2004.
Sagiya, T., S. Miyazaki, and T. Tada, Continuous GPS array and presentday crustal deformation of Japan, Pure Appl. Geophys., 157, 2303–2322, 2000.
Savage, J. C., Displacement field for an edge dislocation in a layered halfspace, J. Geophys. Res., 103, 2439–2446, 1998.
Shinohara, M., T. Kanazawa, T. Yamada, K. Nakahigashi, S. Sakai, R. Hino, Y. Murai, A. Yamazaki, K. Obana, Y. Ito, K. Iwakiri, R. Miura, Y. Machida, K. Mochizuki, K. Uehira, M. Tahara, A. Kuwano, S. Amamiya, S. Kodaira, T. Takanami, Y. Kaneda, and T. Iwasaki, Precise aftershock distribution of the 2007 Chuetsu-oki Earthquake obtained by using an ocean bottom seismometer network, Earth Planets Space, 60, this issue, 1121–1126, 2008.
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Nishimura, T., Tobita, M., Yarai, H. et al. Crustal deformation and a preliminary fault model of the 2007 Chuetsu-oki earthquake observed by GPS, InSAR, and leveling. Earth Planet Sp 60, 1093–1098 (2008). https://doi.org/10.1186/BF03353142
- 2007 Chuetsu-oki earthquake
- crustal deformation