Strong Motion Records of the 2011 Tohoku Earthquake and its Attenuation Characteristics
Saburoh Midorikawa, Hiroyuki Miura, and Tomohiro Atsumi
*Department of Built Environment, Tokyo Institute of Technology, 4259-G3-3 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
Many strong motion records were obtained during the 2011 Off the Pacific Coast of Tohoku earthquake owing to the implementation of dense strong motion observation in Japan. The earthquake provides an opportunity to examine the characteristics of strong ground motion from a gigantic earthquake. Attenuations of peak acceleration and velocity are examined by comparing them to curves from existing attenuation relationships. When the shortest distance from the fault plane of the slip distribution model is used, curves for Mw8.0 to 8.3 give the smallest deviation from data, suggesting the saturation of ground motion intensity at large magnitudes. When the shortest distance from the strong motion generation areas is used, however, the scattering of data becomes smaller and the curve for Mw9.0 fits acceleration data. Results thus change with the definition of distance. This suggests that a consideration of the rupture heterogeneity is important in strong motion prediction for gigantic earthquakes.
-  Earthquake Research Committee, “Evaluations of occurrence potentials of subduction-zone earthquakes along off the pacific Coast of Sanriku to Boso,” p. 36, 2002 (in Japanese).
-  K. Koketsu et al., “A unified source model for the 2011 Tohoku earthquake,” Earth and Planetary Science Letters, Vol.310, Issues 3-4, pp. 480-487, 2011.
-  K. Irikura and S. Kurahashi, “Simulation of strong ground motions from the 2011 Tohoku earthquake and a recipe of predicting strong ground motions,” Japan Geoscience Union Meeting 2012, SSS26-017, 2012.
-  S. Midorikawa, “Strong Motion Networks in Japan – Progress after the 1995 Kobe earthquake –,” Proceedings of the International Symposium on Earthquake Engineering (ISEE Kobe 2005), Vol.1, pp. A-91-A-96, 2005.
-  NIED, 2011, http://www.kyoshin.bosai.go.jp/index_en.html [accessed May 28, 2012].
-  Japan Meteorological Business Support Center, Acceleration Time History Data 2011 DVD, 2012.
-  MLIT, 2011, http://www.nilim.go.jp/lab/rdg/index.htm [accessed May 28, 2012]
-  PARI, 2011, http://www.mlit.go.jp/kowan/kyosin/eq.htm [accessed May 28, 2012]
-  BRI, 2011, http://smo.kenken.go.jp/smdb [accessed May 28, 2012]
-  M. Matsuoka et al., “Average Shear-wave Velocity Mapping Using Japan Engineering Geomorphologic Classification Map,” Journal of Structural Engineering and Earthquake Engineering, JSCE, Vol.23, No.1, pp. 57s-68s, 2006.
-  M. Motosaka and T. Tsamba, “Investigation of High Acceleration Records at K-NET Tsukidate Station During the 2011 Off the Pacific Coast of Tohoku Earthquake,” Proceedings of the 8th Annual Meeting of Japan Association for Earthquake Engineering, pp. 24-25, 2011.
-  H. Si and S. Midorikawa, “New Attenuation Relationships for Peak Ground Acceleration and Velocity Considering Effects of Fault Type and Site Condition,” Journal of Structural and Construction Engineering, A.I.J., No.523, pp. 63-70, 1999 (in Japanese).
-  Skarlatoudis and Papazachos, “Preliminaly Study of the Strong Ground Motions of the Tohoku, Japan, Earthquake of 11 March 2011: Assessing the Influence of Anelastic Attenuation and Rupture Directivity,” Seismological Research Letters, Vol.83, No.1, pp. 119-129, 2012.
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