Abstract
　The Nihonkai Chubu Earthquake of May 26, I983 occurred in the japan Sea about 100 km west off Noshiro port. Akita Prefecture, Japan. According to the JMA, the epicenter of the main shock was located at 40゜2l. 4' N, 139゜04. 6' E, with a focal depth of 14 km. The main shock had a magnitude of 7.7 on the JMA scale. The tsunami from the earhquake was responsible for 104 deaths. The extensive damage to structures was mostly linked to soill liquefaction. Immediately after the earthquake, the resultant damage was investigated in detail and the information to appraise the seismic intensity at many different sites in Akita Prefecture was obtaned by using a questionnaire survey. 11,000 questionnaires were densely distributed throughout Akita Prefecture. Akita Prefecture and Akita City areas were divided into small subareas of 1 km x 1 km, and 250 m x 250 m, respectively, and the seismic intensity for each subarea was evaluated from the responses to questionnaire. A detailed seismic intensity distribution covering Noshiro City was also made as done in the case of Akita City.
　The areas damaged by soil liquefaction were compared with the detailed seismic intensity and the geological subsoil structures in those areas. The detailed seismic intensities were closely related to the geological conditions and thickness of alluvial layers. Moreover, the datailed seismic intensity distributions were correlatrd with the seismic amplification responses which were derived from ground motion by the aftershock of this earthquake.

【KEY WORDS】：Detailed seismic intensity, Damage by soil liquefaction, Geological conditions, Response spectra of ground.

*College of Education, Akita University