@phdthesis{oai:nagoya.repo.nii.ac.jp:00005016, author = {Furumoto, Muneyoshi and 古本, 宗充}, month = {Oct}, note = {The phase equalization was carried out for R waves in order to obtain the information on the source mechanisms of the four earthquakes, the Kurile earthquake of 1963, its largest aftershock,the Rat Is.earthquake of 1965, and the Tokachi-oki earthquake of 1968. Initial phase was computed using the corresponding complete great-circle phase velocity, so that the influences of the lateral heterogeneity of the earth's structure were considerably reduced. The fault length of the Kurile earthquake was determined from the initial phase radiation pattern on the basis of a simple propagating fault model. There is no trade=off in this method between the fault length and the rupture velocity. Such a trade-off is inherent to the conventional directivity method. A fault length of 250 Km was obtained, which was found to be nearly equal to the length of the aftershock area. We have introduced a dynamic fault parameter `source time' that can be determined from the phase measurement using the complete great-circle phase velocity rather than the average phase velocity of individual multiple R waves. This quantity corresponds to the rise time of the source time function of an equivalent point source. Source times of 97,62,174, and 115 sec were obtained for the above four earthquakes., 名古屋大学博士学位論文 学位の種類:理学博士 (論文) 学位授与年月日:昭和54年10月12日}, school = {名古屋大学, Nagoya University}, title = {Initial Phase Analysis of R Waves from Great Earthquakes}, year = {1979} }