Report on Kikai (Japan) — January 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 1 (January 1988)
Managing Editor: Lindsay McClelland.
Kikai (Japan) Small ash plumes; first known since 1935
Please cite this report as:
Global Volcanism Program, 1988. Report on Kikai (Japan). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 13:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198801-282060.
30.793°N, 130.305°E; summit elev. 704 m
All times are local (unless otherwise noted)
Gray plumes were ejected to 400-500 m above the summit crater of Iwo-dake on 18 January at 0830, 1030, 1640, and 1745. No air or ground shocks were felt by residents. Ash fell on the SE part of the island that evening. When observed from the air on 20 January, the white steam plume was a little larger than usual. A field party at the summit crater 26-28 January measured a fumarole temperature of 788°C, almost the same as in 1985.
Geologic Background. Kikai is a mostly submerged, 19-km-wide caldera near the northern end of the Ryukyu Islands south of Kyushu. Kikai was the source of one of the world's largest Holocene eruptions about 6300 years ago. Rhyolitic pyroclastic flows traveled across the sea for a total distance of 100 km to southern Kyushu, and ashfall reached the northern Japanese island of Hokkaido. The eruption devastated southern and central Kyushu, which remained uninhabited for several centuries. Post-caldera eruptions formed Iodake lava dome and Inamuradake scoria cone, as well as submarine lava domes. Historical eruptions have occurred in the 20th century at or near Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island forming part of the NW caldera rim. Showa-Iojima lava dome (also known as Iojima-Shinto), a small island 2 km east of Tokara-Iojima, was formed during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive eruptions have occurred during the past few decades from Iodake, a rhyolitic lava dome at the eastern end of Tokara-Iojima.
Information Contacts: JMA.