Report on Kirishimayama (Japan) — 18 October-24 October 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 18 October-24 October 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Kirishimayama (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 18 October-24 October 2017. 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 eruption at Shinmoe-dake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, began on 11 October and lasted almost continuously until the morning of 17 October. The eruption plume usually rose several hundred meters about the crater rim, though on 14 October the plume rose as high as 2.3 km. Sulfur dioxide flux exceeding 10,000 tons/day was also recorded. Cloudy weather conditions prevented webcam views during 19-20 October. Plumes rose 200-600 m on 21, 23, and 24 October. During an overflight on 24 October scientists observed a white plume rising from the active vent on the E side of the crater, and puddles in multiple low areas of the crater. The Alert Level remained at 3 (on a scale of 1-5).
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.