Recently the Asahi News reported the following:
The Coordinating Committee for Prediction of Volcanic Eruption of the Meteorological Agency (Chairman Toshitsugu Fujii, professor emeritus of the University of Tokyo) was held on the 22nd, and it was reported that seismic activities were activated in three volcanoes (Mt. Fuji, the Mt. Hakone (Kanagawa Prefecture), and Yakedake (Gifu and Nagano prefecture boundary)). It was said that there was no change in the volcanic activity although it was thought that the influence of a East Japan great earthquake could be seen. On the 11th, at Yakedake and the Mt. Hakone, earthquake had occurred one after another immediately after the occurrence of the 9.0 magnitude East Japan great earthquake, the shake observed was at the magnitude of 2-3 in seismic intensity. A shake at an intensity over 6 was observed in prefecture in which the Fujinomiya City lied and Mt. Fuji existed as a result of the magnitude 6.4 earthquake occurred in the east part of Shizuoka Prefecture on the 15th. It was said that afterwards aftershocks continued.
The Meteorological Agency believed that "There is neither volcanic tremor nor changes in the earth's crust, and the symptom of the volcanic activity is not found".
Chairman Fujii made the point that ｢While it is true that some of the volcanoes in Japan have reacted, whether it is the direct influence of the magnitude 9.0 earthquake is not understood. The seismic activity around the volcano is having a reducing tendency, and probably nothing will happen right now. However, in the Sumatra earthquake in 2004, it is only after several months have passed that the volcanic activity in Indonesia is reactivated; so it is necessary to pay attention from now on｣.
At present, it is difficult to know whether the East Japan great earthquake will cause further earthquakes. Using the Sumatra earthquake as the example, it is useful to stay alert in the coming few months.