This research paper describes an on-going earthquake observation project in Sendai, Japan. The observation system includes 11 observation sites and a control station. A number of records with intermediate amplitudes have been obtained to this date.

In this report, the earthquake observation system is introduced at first. The description includes the outline of the geological condition of the Sendai area,the objective area of the observation, the surface geology of the 11 observation sites from the investigation in sites, and the recorded data by the fiscal year of 1990.

During the period, the seismic activity of the area was not so high.Therefore, the accelerograms whose amplitudes are large enough to be called"strong motion" were not recorded. However, these data are essential for the purpose to examine the dynamic amplification property of the surface soils.

In this report, some analytical results utilizing the records are added.

In the appendix, the wave forms and the response spectra of the selected recorded motions are given. The records are to be open to the public after period of processing under the agreement with the co-researchers.

^*1 Director, International Institute of Seismology and Earthquake Engineering
^*2 Head, Geotechnical Engineering Division, Structural Engineering Department
^*3 Research Staff, International Institute of Seismology and Earthquake Engineering