- Open Access
Strong ground motions recorded by a near-source seismographic array during the 16 August 2005 Miyagi-Ken-Oki, JAPAN, earthquake (Mw 7.2)
Earth, Planets and Space volume 58, pages1555–1559(2006)
An earthquake of Mw 7.2 took place on August 16, 2005 at a plate boundary between the Pacific plate and the North American plate off the coast of Miyagi Prefecture, Northeast Japan. During the Miyagi-Ken-Oki event, we succeeded in recording strong ground motions at six stations in a seismograhic array with an epicentral distance of about 70 km, where we have been operating seven strong-motion seismometers in an aperture of about 500 m since April 2004. The predominant period of the ground motion was shorter than 0.3 s. The peak ground acceleration exceeded 1.7 g at a station where non-linear site response may have occurred during the mainshock. The short-period strong ground motions show a large spatial variation, with up to a ten-fold difference in amplitude even within the array. However, there is a similarity between waveforms registered at different stations for periods longer than 0.4 s. Therefore, the difference in the ground motions may be mainly attributed to the difference in the shallow structure just beneath the stations.
Architectural Institute of Japan, Jiban Shindou—Genshou to Riron, Architectural institude of Japan, Tokyo, 2005 (in Japanese).
Editorial committee of geologic atlas of Japan, Geologic atlas of Japan—Tohoku region, Asakura Shoten, Tokyo, 1992.
Field, E. H., P. A. Hohnson, I. A. Beresnev, and Y. Zeng, Nonlinear ground-motion amplification by sediments during the 1994 Northridge earthquake, Nature, 390, 599–602, 1997.
Geographical Survey Institute, Crustal movements in the Tohoku district, Rep. Coord. Comm. Earthq. Pred., 75, 75–114, 2006 (in Japanese with English figure captions).
Goldstein, P. and R. Archuleta, Deterministic frequency-wavenumber methods and direct measurements of rupture propagation during earthquakes using a dense array: Data analysis, J. Geophys. Res., 96, 6187–6198, 1991.
Sakai, Y., T. Kanno, and K. Koketsu, Proposal of instrumental seismic intensity scale from response spectra in various period ranges, J. Struct. Constr. Eng., AIJ, 585, 71–76, 2004.
Spudich, P. and E. Cranswick, Direct observation of rupture propagation during the 1979 Imperial Valley, California, earthquake using a short baseline accelerometer array, Bull. Seismol. Soc. Am., 74, 2083–2114, 1984.
The headquarters for earthquake research promotion (HERP), List of long-term evaluation, (web address: http://www.jishin.go.jp/main/choukihyoka/kaikou.htm), 2005 (only in Japanese).
Wessel, P. and W. H. F. Smith, New improved version of the Generic Mapping Tools released, EOS Trans., Am. Geophys. Union, 79, 579, 1998.
About this article
Cite this article
Nakahara, H., Sawazaki, K., Takagi, N. et al. Strong ground motions recorded by a near-source seismographic array during the 16 August 2005 Miyagi-Ken-Oki, JAPAN, earthquake (Mw 7.2). Earth Planet Sp 58, 1555–1559 (2006). https://doi.org/10.1186/BF03352660
- Miyagi-Ken-Oki earthquake
- strong ground motion
- spatial variation
- non-linear site response