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Report on Aira (Japan) — March 1988

Scientific Event Alert Network Bulletin, vol. 13, no. 3 (March 1988)
Managing Editor: Lindsay McClelland.

Aira (Japan) Strong explosions

Please cite this report as:

Global Volcanism Program, 1988. Report on Aira (Japan). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 13:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198803-282080.

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 recorded explosions . . . declined from 35 in February to 21 in March . . . . The explosions often ejected large amounts of lapilli onto the flanks. At [KLMO], March ash accumulation totaled 934 g/m2; 15 explosion sounds were heard and 19 air shocks were felt there during the month.

An explosion on 27 March at 1252, accompanied by a loud sound and strong air shock, ejected an ash cloud that rose more than 4,000 m above the crater. Flank lapilli fall was heavy, breaking windshields of two cars at the E foot of the volcano, and the air shock cracked two windows at a hotel.

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.