Report on Kirishimayama (Japan) — 18 December-24 December 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 18 December-24 December 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Kirishimayama (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 18 December-24 December 2019. Smithsonian Institution and US Geological Survey.
31.934°N, 130.862°E; summit elev. 1700 m
All times are local (unless otherwise noted)
JMA reported that the increase in the number of volcanic earthquakes with hypocenters just below Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, only lasted during 17-18 November. The number of volcanic earthquakes was low after that and no other data indicated increased activity. Scientists noted no changes to geothermal areas on the crater floor and below cracks on the W flank during a field survey on 12 December. The Alert Level was lowered to 1 (on a scale of 1-5) on 20 December.
Geologic Background. 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.