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Report on Aira (Japan) — April 2003


Bulletin of the Global Volcanism Network, vol. 28, no. 4 (April 2003)
Managing Editor: Edward Venzke.

Aira (Japan) Ash plume observed in July 2002; plume photo from 17 April 2003

Please cite this report as:

Global Volcanism Program, 2003. Report on Aira (Japan) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 28:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200304-282080



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

All times are local (unless otherwise noted)

An observer at Kagoshima Airport reported seeing an ash cloud from Sakura-jima at 0900 on 22 July 2002 that rose to 2.1-2.4 km altitude. An ash plume was visible on satellite imagery at 1052 (0152 UTC) that day extending to the SW.

A photograph taken by the webcam at ttp://yumemaru.com/s/ shows a plume of undetermined composition originating from the island on 17 April 2003 (figure 22). This type of event is common at Sakura-jima.

Figure (see Caption) Figure 22. Photograph of Sakura-jima taken on 17 April 2003 showing a plume originating from the island. Courtesy of Yunemaru.

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: Charles Holliday, U.S. Air Force Weather Agency, 106 Peacekeeper Drive, Ste 2NE, Offut AFB, NE 68113-4039, USA (URL: http://www.557weatherwing.af.mil/); Yunemaru (URL: http://yumemaru.com/).