Turkish strong ground motion data acquisition and analysis

Abstract

The installation of a strong-motion network in Turkey was initiated in 1973 under the sponsorship of the Earthquake Research Institute. Today, 61 accelerographs and 40 seismoscope stations have been installed along the most active seismic zones, namely the North Anatolian zone and in the graben systems of western Anatolia. All the strong ground motion records, which were obtained during the period 1973–1983, are listed in the tables. The date, origin time and body-wave magnitude of the events are given together with the local intensity, focal distance of the recording station and maximum acceleration registered by the instrument. Information about the significant earthquakes, which were recorded by SMA-1 Kinemetrics type accelerographs, are also given in the following. August 19, 1976 Denizli earthquake in western Anatolia with a magnitude 4.7, caused considerable damage in the city. It is interesting to note that this was the first earthquake whose strong motion was recorded by an accelerograph located within the epicentral area. The baseline corrected acceleration and velocity values for the N-S component is calculated to be 34.21% g and 21.35 cm s −1. November 24, 1976 Çaldiran earthquake in eastern Anatolia showed the spectral acceleration of 11.2% g for a natural period of 0.73 s. December 9 and 16, 1977 İzmir earthquakes with magnitudes 4.8 and 5.3 caused damage at various locations in İzmir. The two earthquakes were recorded by a SMA-1 and by two seismoscopes, and showed the acceleration values reaching 21% g in the E-W component. The strong-motion accelerographs of the other earthquakes that occurred in the 1973–1982 period were also processed and preliminary evaluation of the data was studied taking the damage distribution and the site conditions into consideration.