Fault model of the 1964 off Oga earthquake as a tsunami source

Source model of tsunami was derived based on correlation coefficients of peaks and troughs between observation and model. In the trial model parameters were systematically varied under constraints of seismic moment, central position and length of the fault. Thus other five parameters were determined from the maximum values of correlation coefficient. This method was applied to tsunami of the 1964 Off Oga Earthquake and a fault model was derived having sizes of 50 km (length), 20 km (width), 0.96 m (dislocation) , angles of N20°E (strike), 30°E (dip) , 90°(slip), and position of 40.32°N (latitude), 138.95°E (longitude), 5 km (depth). It is found that the fault plane almost coincides to south one of two fault planes of the 1983 Japan Sea Earthquake. From this coincidence it is concluded that this earthquake was a precursor of the 1983 Japan Sea Earthquake.