부산대학교 도서관

Volcanoes in Hokkaido had vigorous eruption histories in the last 400 years. Especially in the southern Hokkaido, Hokkaido-Komagatake, Usuzan, and Tarumaesan, reawakened in the 17th century after the long-dormant period and vigorous magmatic eruptions of VEI5 class have been recorded in the historical literature and also in geological layers. Contrary to these volcanoes, we have documented histories only after the 20th century for Tokachidake and Meakandake. Continuous volcano monitoring has been performed in major active volcanoes in Hokkaido since 1960s. In the 1970s, with the increase in seismic activity of Tokachidake, sponsored research from Hokkaido Government to Hokkaido University began to establish disaster management plans for future eruptions of active volcanoes in Hokkaido, and research reports was edited by Hokkaido University. Although 50 years have passed since the publication of the first report on Tokachidake, the reports of the research on active volcanoes are still one of the first documents to be referred when investigating the past activities of volcanoes in Hokkaido and the results of old scientific surveys. In addition, the reports include interdisciplinary contents for that time such as prediction of future eruptive activities and disaster prevention measures. The sponsored research by Hokkaido Government has continued to the present, and a new report on Tokachidake was published in 2014. The compilation of such research reports is very effective for volcano researchers and for relating field to share their awareness of the problems of volcanoes beyond their individual fields of expertise. Monitoring network around the active volcanoes in Hokkaido has been remarkably improved for these 20 years by Japan Meteorological Agency (JMA), Hokkaido University and other relating institutions. Recent data exchange in real-time among different organizations reduces duplication of monitoring resources and increases multi-parameter monitoring ability. The improved volcano monitoring network is expected to detect precursory activities of future magmatic eruptions concerned at the major volcanoes. Looking back on the eruption in the 20th century in Hokkaido, small phreatic eruptions preceded magmatic vigorous eruptions in many cases. Not only mountaineers but also tourists and citizens can easily approach the crater area without any special equipment at several active volcanoes, so even a small eruption can lead to severe volcanic disaster.