The Tokyo VAAC reported that on 15 May ash plumes from Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, were identified in satellite images drifting S at an altitude of 7.6 km (25,000 ft) a.s.l. JMA noted that white plumes rose 100 m above the crater rim during 18-21 May. The Alert Level remained at 3 (on a scale of 1-5).

Geological Summary. Kirishimayama is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene dominantly andesitic group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located Karakunidake being the highest. Onamiike and Miike, the two largest maars, are located SW of Karakunidake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century.

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)