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Rupture process at the beginning of the 2007 Chuetsu-oki, Niigata, Japan, earthquake
Earth, Planets and Space volume 61, pages279–283(2009)
The rupture process at the beginning stage of the 2007 Chuetsu-oki, Niigata, Japan, earthquake (MW 6.6) is investigated by analyzing P-wave records from local strong-motion stations. The P-wave portion of the nearsource strong-motion records shows about 2 s of small but increasing amplitude arrival (so-called “initial rupture phase”) followed by the onset of the main energy release (“main rupture phase”). Two issues are addressed in this paper: (1) where the initial rupture process occurred and (2) where the seismic energy corresponding to the main rupture phase was released at the primary stage of the main rupture. The first issue is addressed by locating the main rupture onset position, and the second issue is then approached by introducing a method for mapping the wave energy onto plausible fault planes. Eventually, the following were revealed. The rupture initiated and propagated on the NW-dipping plane, which is a nodal plane of the focal mechanism solution. At 2.1 s after rupture initiation the subsequent main rupture started at a position of approximately 4 km away, southwestward and updipward from the hypocenter. The main rupture at this stage has two possible rupture planes: the same plane as the initial rupture plane, and the conjugated plane, which shares the main rupture onset point with the initial rupture plane. Although it is difficult to determine which plane was actually ruptured at the primary stage of the main rupture, we found that the possible areas radiating strong wave energy on the two possible planes, which could correspond to the first asperity of this earthquake, are located between the hypocenter and the Kashiwazaki-Kariwa nuclear power plant.
Abercrombie, R. and J. Mori, Local observations of the onset of a large earthquake, 28 June 1992 Landers, California, Bull. Seismol. Soc. Am., 84, 725–734, 1994.
Hirata, M., The Initial Rupture Process of 2000 Western Tottori Earthquake, 28 pp., Master Thesis, Kyoto University, 2003.
Hirata, M., Y. Umeda, and H. Kawakata, Initial rupture of the 2000 Western Tottori earthquake, Chikyu Monthly, special issue, 38, 162–166, 2002 (in Japanese).
Irikura, K., T. Kagawa, K. Miyakoshi, and S. Kurahashi, Rupture process and strong ground motions of the 2007 Niigataken Chuetsu-Oki earthquake—Directivity pulses striking the Kashiwazaki-Kariwa Nuclear Power Plant—, AGU, Fall Meeting, S31B–0441, 2007.
Ishii, M., P. M. Shearer, H. Houston, and J. E. Vidale, Rupture extent, duration, and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-Net array, Nature, 435, doi:10.1038/nature03675, 2005.
Kao, H. and S.-J. Shan, The source-scanning algorithm: Mapping the distribution of seismic sources in time and space, Geophys. J. Int., 157, 589–594, 2004.
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, 1111–1116, 2008.
Miyake, H. and K. Koketsu, Source modeling and broadband ground motion simulation for the 2007 Niigata-ken Chuetsu-oki earthquake, Seismol. Soc. Japan, Fall Meeting, P1–076, 2007 (in Japanese).
Sakai, S., A. Kato, E. Kurashimo, T. Igarashi, T. Iidaka, T. Iwasaki, N. Hirata, T. Kanazawa, and the group for the joint aftershock observation of the Niigataken Chuetsu-oki Earthquake in 2007, Aftershock observation of the Niigataken Chuetsu-oki Earthquake in 2007 by temporary seismic observations, Seismol. Soc. Japan, Fall Meet., P1–060, 2007 (in Japanese).
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, 1121–1126, 2008.
Takenaka, H., T. Nakamura, Y. Yamamoto, G. Toyokuni, and H. Kawase, Precise location of the fault plane and the onset of the main rupture of the 2005West Off Fukuoka Prefecture earthquake, Earth Planets Space, 58, 75–80, 2006.
Ueno, H., S. Hatakeyama, T. Aketagawa, J. Funasaki, and N. Hamada, Improvement of hypocenter determination procedures in the Japan Meteorological Agency, Q. J. Seismol., 65, 123–134, 2002 (in Japanese with English abstract).
Yamaguchi, S., H. Kawakata, T. Adachi, and Y. Umeda, Features of initial process of rupture for the 2005West off Fukuoka Prefecture earthquake, Zisin (J. Seismol. Soc. Jpn.), 59, 241–252, 2007 (in Japanese with English abstract).
Yamamoto, Y. and H. Takenaka, Rupture process of the 2007 Noto Hanto earthquake inferred from local P-wave records: second hypocenter, initial rupture, main rupture, asperity and killer pulse, AGU, Fall Meeting, S13A–1059, 2007.
Yukutake, Y., T. Takeda, and K. Obara, Well-resolved hypocenter distribution using the double-difference relocation method in the region of the 2007 Chuetsu-oki Earthquake, Earth Planets Space, 60, 1105–1109, 2008.
Wald, D. J., D. V. Helmberger, and T. H. Heaton, Rupture model of the 1989 Loma Prieta earthquake from the inversion of strong-motion and broadband teleseismic data, Bull. Seismol. Soc. Am., 81, 1540–1572, 1991.
Wessel, P. and W. H. F. Smith, New version of the generic mapping tools released, Eos Trans. AGU, 76, 329, 1995.
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Takenaka, H., Yamamoto, Y. & Yamasaki, H. Rupture process at the beginning of the 2007 Chuetsu-oki, Niigata, Japan, earthquake. Earth Planet Sp 61, 279–283 (2009). https://doi.org/10.1186/BF03352908
- 2007 Chuetsu-oki earthquake
- fault plane
- source process
- initial rupture