JMA reported that during 10-17 July data from the Global Navigation Satellite System (GNSS) indicated continuing minor inflation at shallow depths beneath Ioyama, located on the NW flank of the Karakuni-dake stratovolcano in the Kirishimayama volcano group. A few shallow volcanic earthquakes were recorded. Vigorous fumarolic activity was visible at the fumarolic are on the S side of Ioyama. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay 1 km away from Ioyama.

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.

Source: Japan Meteorological Agency (JMA)