Investigation on earthquake prediction in Kamchatka

Investigations on earthquake prediction in Kamchatka are mainly carried out along three lines: 1. (1) The detailed investigations of Kamchatka-Komandorskiye Islands seismicity laws and long-term prediction (“seismic weather prediction”). The location of the Japanese earthquake on May 16, 1968, M = 7.9 was predicted well. 2. (2) The investigation of the connection between earthquakes and irregularities of electrotelluric field. The observed electric anomalies are found to arise some hours before the earthquakes and at the moment of the shock. The periods of such irregularities change from some minutes to half an hour. The amplitudes reach 50 mV/km. 3. (3) Investigations of velocities, amplitudes and other features of P-wave in the Pacific seismic focal zone near Kamchatka and their variations in time. Places of shot points and receivers at coast and in the ocean were constant. Distances were 40–200 km. Standard deviations of traveltime determinations were there ± 0.03 sec. In 1966–1968, when there were no earthquakes with M ≥ 6 in the investigated region, travel-time variations were in error limits. That means P velocities were constant here with an accuracy of 0.3–0.5%