富士火山の地震活動

概要

論文の詳細を見る
Mt. Fuji, the highest peak in Japan, is one of the largest and most famous volcanoes which have displayed violent volcanic eruptions in historic times. It may easily be supposed that Mt. Fuji has the potential of erupting in the future. Therefore, in terms of its social impact, Mt. Fuji is one of the most dangerous volcanoes in Japan. In order to accurately predict volcanic eruptions from seismological observations, it is very important to clarify the detailed seismic activity of the volcano. We carried out temporal seismometrical observations of Mt. Fuji in 1969, 1970 and 1972. From the analysis of the temporal observational data combined with the data obtained by the routine observations of other observatories, the seismicity of Mt. Fuji may be summarized as follows: 1) Seismic activity identifiable as directly related to the volcanic activity was not found by the temporal observations carried out on and around Mt. Fuji. 2) Only three earthquakes with a magnitude over 3.0 occurred beneath the body of Mt. Fuji proper during the past 18 years, from Jan. 1961 to Dec. 1978. The seismic activity inside Mt. Fuji seems rather low compared to that in the area around Mt. Fuji. 3) The analysis of the distribution of P-wave initial motions of the earthquakes which occurred inside Mt. Fuji indicates the existence of horizontal compressional stresses in the direction NW-SE.
1981-09-30