In Japan there are about 200 Quaternary volcanoes, including about 77 active volcanoes. They provide us with various kinds of natural resources and beautiful sceneries. 0n the other hand, we have been suffering from volcanic disasters since the dawn of history. Scientific study of our volcanoes commenced soon after the Meiji Restoration of 1868, and the first volcano observatory in our country was established on the flank of Asama-yama, Central Honsyu, in 1911 by the Imperial Earthquake Investigation Committee in cooperation with Nagano Meteorological 0bservatory. Thereafter many volcano observatories were established by the Japan Meteorological Agency (JMA) and various univeersities. In recent years, due to rapid increase in number of climbers and tourists coming to those active volcanoes and of inhabitants near them, the danger to human lives and properties in case of eruptions of those volcanoes has been enlarged year after year. The volcanological task of the JMA has been expanding rapidly after the 2nd World War. Especially, since 1962, the JMA has been making every effort to establish systematic observation and research of all active volcanoes in Japan. 10 of our active volcanoes are situated on Kunashir and Iturup Islands, now occupied by the USSR, so the JMA is responsible for the surveillance of about 67 active volcanoes for the time being, ana divides them into three classes (A,B and C), depending upon the natural and social conditions of the respective volcano.
