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Strong ground motions recorded by a near-source seismographic array during the 16 August 2005 Miyagi-Ken-Oki, JAPAN, earthquake (Mw 7.2)


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.


  1. Architectural Institute of Japan, Jiban Shindou—Genshou to Riron, Architectural institude of Japan, Tokyo, 2005 (in Japanese).

    Google Scholar 

  2. Editorial committee of geologic atlas of Japan, Geologic atlas of Japan—Tohoku region, Asakura Shoten, Tokyo, 1992.

    Google Scholar 

  3. 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.

    Article  Google Scholar 

  4. Geographical Survey Institute, Crustal movements in the Tohoku district, Rep. Coord. Comm. Earthq. Pred., 75, 75–114, 2006 (in Japanese with English figure captions).

    Google Scholar 

  5. 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.

    Article  Google Scholar 

  6. 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.

    Google Scholar 

  7. 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.

    Google Scholar 

  8. The headquarters for earthquake research promotion (HERP), List of long-term evaluation, (web address:, 2005 (only in Japanese).

    Google Scholar 

  9. Wessel, P. and W. H. F. Smith, New improved version of the Generic Mapping Tools released, EOS Trans., Am. Geophys. Union, 79, 579, 1998.

    Article  Google Scholar 

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Correspondence to Hisashi Nakahara.

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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).

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Key words

  • Miyagi-Ken-Oki earthquake
  • array
  • strong ground motion
  • spatial variation
  • non-linear site response