薩南諸島域の地震火山活動

Abstract

The historical activity of volcanoes in Satsunan Islands, lieing on the southern sea of KyushuIs., Japan, are inspected. Two seismic observations on Amami-O-shima Is. (1969) and on Okino-erabu-jima Is. (1973) were carried out to examine the presently seismic and volcanic activity inthe region. The results obtained are as following; (1) the volcanoes in Kuchierabo-jima, Suwanose-jima and Torishima have been active, (2) the remarkable close correlation among the activitiesof each volcanoes in the region are not found, except on the violent eruption of Sakurajima volcanoin 1914, (3) the seismic activity around Amami-O-shima is higher than that around Okierabo-jima, and (4) the foci of earthquakes are deeper in the east of the Is. Than in the west and this seems tobe reasonable to the fact that the volcanic islands lie in the west side of the main Satunan Is. On whichthe seismic stations are set.