Logo link to homepage

Report on Aira (Japan) — 1 November-7 November 2023


Aira

Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 1 November-7 November 2023
Managing Editor: Sally Sennert.

Please cite this report as:

Global Volcanism Program, 2023. Report on Aira (Japan) (Sennert, S, ed.). Weekly Volcanic Activity Report, 1 November-7 November 2023. Smithsonian Institution and US Geological Survey.

Weekly Report (1 November-7 November 2023)

Aira

Japan

31.5772°N, 130.6589°E; summit elev. 1117 m

All times are local (unless otherwise noted)


JMA reported ongoing activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano) during 30 October-6 November, with incandescence at the crater observed nightly. Sulfur dioxide emissions averaged 1,300 tons per day on 2 November. There was a total of 10 eruptive events recorded during 30-31 October and 1-2 November. Ash plumes rose as high as 1.8 km above the crater rim and drifted N, E, and SE. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.

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 caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76.

Source: Japan Meteorological Agency (JMA)