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Report on Aira (Japan) — June 1982

Scientific Event Alert Network Bulletin, vol. 7, no. 6 (June 1982)
Managing Editor: Lindsay McClelland.

Aira (Japan) Frequent explosions; tephra cause minor damage

Please cite this report as:

Global Volcanism Program, 1982. Report on Aira (Japan). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 7:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198206-282080.

Volcano Profile |  Complete Bulletin


Aira

Japan

31.593°N, 130.657°E; summit elev. 1117 m

All times are local (unless otherwise noted)


The number of explosions from the summit crater of Minami-dake increased from [24] in May to 34 in June. A 300-m-high incandescent column was observed at 2223 on 8 June, and the highest plume rose 3000 m above the summit on 10 June. Carried by a strong wind, ejecta from the explosion at 0325 on 14 June fell in the area between Kurokami (4.7 km E of the crater) and Sakura-jima-guchi (5.5 km SE). At Kurokami, lapilli broke a car windshield and a building's windowpane.

Geologic Background. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.

Information Contacts: JMA, Tokyo.