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Report on Aira (Japan) — December 1978

Scientific Event Alert Network Bulletin, vol. 3, no. 12 (December 1978)
Managing Editor: David Squires.

Aira (Japan) Only one explosion in November; ash ejection between explosions ends

Please cite this report as:

Global Volcanism Program, 1978. Report on Aira (Japan). In: Squires, D. (ed.), Scientific Event Alert Network Bulletin, 3:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197812-282080.

Volcano Profile |  Complete Bulletin


Aira

Japan

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

All times are local (unless otherwise noted)


Only one explosion from the summit crater of Minami-dake was recorded during November, on the 15th. The ash ejection that had frequently occurred between explosions since the spring ended about 25 November. Activity has been limited to steam emission since then.

Further Reference. Kamo, K., 1979, The Recent Activity of Sakura-jima Volcano; in Report on Volcanic Activities and Volcanological Studies in Japan for the Period from 1975 to 1978; Bulletin of the Volcanological Society of Japan, v. 24, no. 4, p. 26-34.

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.