南九州の地震

Abstract

This paper is composed of 3 articles, and their abstracts are as followes.1) The epicenter distrihution of the earthquakes in and near Kyllshn during l967-~68 after"The Seismological Bulltin of J.M.A." is divided three zones (the West Japan Volcanic Belt, theEast side and the West side zones), which show the parallel arrangement to NE-SW direction. Thedepthes of hypocenters in each zone are plotted, and it showes that the earthquakes deeper than100 km only occurred in Volcanio Belt zone.2) The time-distance curves for P and S waves in Kynshil are obtained from the observationresults of "Ebino earthquake swarm", and the curstal structure are estimated by them. Andalso, the tendency is recognized that the arrival times of S wave late from the time-distance curveat the stations where seismic wave run cross the active volcanic areas, Krishima, Sakurajima, Aso, and Unzen.3) To examine the seismic activity near and at Amami-Oshima, the daily frequency, the S-Ptime distribution and the frequency-amplitude relation of the earthquakes at Naze city aredescribed.