CHARACTERISTICS OF THE GROUND MOTION OF THE 1997 KAGOSHIMAKEN-HOKUSEIBU EARTHQUAKE

The earthquakes which occurred in the northwestern part of Kagoshima prefecture on March 26 and May 13 in 1997 caused severe damage to some reinforced concrete school buildings and wooden houses. Many ground motion records are obtained by the seismographs of JMA and NIED which settled in high density after 1995 Hyogoken-Nanbu Earthquake. The response spectra of the ground motion of four sites which surround the seismic region are analyzed. The large peak ground accelerations such as 728 cm/s^2 at Izumi or 902 cm/s^2 at Miyanojyo are recorded but did not cause no severe damage of buildings near seismographs. These records contain predominant high frequencies of over 5 Hz. The response spectra of four sites are different by the location to the seismic region.