Name : KUDO,  Kazuyoshi
            Position : Associate Professor
            Division/Center : Division of Disaster Mitigation Science
            Research Area : Strong Motion Seismology, Engineering Seismology
 
 
 

Our major subject is observational approaches on the generation and propagation of strong ground motion．The observed strong ground
motion is a resultant of high frequency waves radiated from a source and effects of propagation path as well as local geologic conditions on
seismic waves. Our current topics are:

    1.Discriminating a high-frequency limit (fmax) found in source spectra, we postulated a rapid decrease of rupture propagation velocity
       as a cause of fmax. The source-controlled fmax was examined by using the data set of strong motion records from swarm earthquakes
       occurred near Izu peninsula.
    2.Because strong ground motions are characterized by high frequency or short wave length, they are affected by near surface geology
       that is generally complex and heterogeneous. In order to evaluate quantitatively the effects of geologic structure on strong ground
       motion, we have successively carried out strong motion observation and geophysical/geotechnical survey in Ashigara valley. This
       project has been based on the framework of international cooperative study (IASPE/IAEE).
    3.We have developed a new strong motion sensor which is a highly damped (h=25-30) moving-coil type accelerometer covering a wide
       frequency range (0.1-80 Hz). The portable seismograph with this sensor and the 24-bits data-logger has provided quick
       deployments of temporal observation network of strong as well as weak motion and array observation of microtremors for determining
       S-wave velocity structures in urban area.

 Publications:

Kudo, K., T. Kanno, H. Okada, O. Ozel, and M. Erdik , Microtremors and Aftershock Observations, (Included in Progress Report on Damage Investigation after Kocaeli Earthquake by Architectural Institute of Japan, Architectural Institute of Japan Reconnaissance Team and Bogazici University, Istanbul Technical University, Middle East Technical University), International Journal for Housing Science and Its Applications, 24, 1, 99--104, 2000.