Report on Aira (Japan) — November 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 11 (November 1991)
Managing Editor: Lindsay McClelland.
Aira (Japan) Continued explosions
Please cite this report as:
Global Volcanism Program, 1991. Report on Aira (Japan) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 16:11. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199111-282080
31.593°N, 130.657°E; summit elev. 1117 m
All times are local (unless otherwise noted)
Fifteen explosions were recorded in November . . . . A car windshield was cracked by lapilli from the month's highest ash cloud (3,000 m), emitted at 1245 on 18 November. A total of 332 g/m2 of ash was deposited [at KLMO] in November . . . . Swarms of volcanic earthquakes were recorded on 3, 5, 10, 19, and 28 November.
Geological Summary. 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.