Name : SHIMAZAKI,  Kunihiko
            Position : Professor
            Division/Center :  Division of Earth Mechanics
            Resarch Area : Long-term Earthquake Forecast
            homepage : http://www.eri.u-tokyo.ac.jp/nikosh/nikosh.html
 
 
 

Research:

       Recurrence behavior of earthquakes is a major target of my research at present. Together with Stirling and Wesnousky, I carried out
       world-wide survey of fault trace of major strike-slip faults and study of seismicity around the them, especially comparison of the
       observed seismicity with a theoretical estimate derived from the Gutenberg-Richter relationship. We found out that the density of
       fault steps decreases with an increase of total offset and that the ratio of theoretical estimate to the observed number of earthquakes
       amounts to larger than ten in general. This suggests an evolutionary concept that wearing process on the fault decreases complexity
       of fault trace and results in a production of so-called characteristic earthquake. The other aspect of earthquake recurrence was
       obtained from a study on branching feature of active faults carried out with Nakata and others. We found that the actual rupture
       propagation is consistent with the branching feature of surface rupture (Y-shaped trace is produced by a rupture propagating upward)
       for recent large earthquakes. The branching of surface rupture was repeated by the 1940 and 1979 Imperial Valley earthquake. Also
       seismic profiling records of submarine fault in Beppu Bay shows a repetition of branching. Thus the branching feature of active fault
       suggests a repetition of rupture propagation in the same direction.

Publications:

Shimazaki, K., and Y. Zhao, Dislocation model for strain accumulation in a plate collision zone, Earth Planets Space, 52, 1091--1094, 2000.

Shimazaki, K., The Almighty Earthquake, Seismol. Res. Lett., 70, 147--148, 1999.

 Wyss, M., K. Shimazaki, and A. Ito, Introduction - seismicity patterns, their statistical significance and physical meaning, Pure Appl. Geophys., 115, 203--205, 1999.