The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano) during 30 December 2024-6 January 2025. Nightly crater incandescence was visible in webcam images. Eruptive events at 1317 and 2029 on 31 December, at 0658 and 1443 on 1 January, at 1335 and 2224 on 2 January, and 1002 and 1045 on 5 January produced ash plumes that rose 1-1.4 km above the crater rim and drifted NE, E, and SE. Explosions at 1317 and 2029 on 31 December, at 0348 on 3 January, at 0125 on 4 January, and at 1002 and 1045 on 5 January produced ash plumes that rose 0.5-1.5 km above the crater rim and drifted S and SE. All of the explosions, except at 1451 on 6 January, ejected large blocks 300-900 m from the crater rim. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 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)