James Reynolds 4 hours
Eruption reported by Tokyo VAAC at Satsuma-Iojima, just south of Kyushu. First eruption I've seen reported there


Erik Klemetti 4 hours
Is that the same as Satsuma-Iwo Jima?

James Reynolds 4 hours
I would imagine so, per VAAC map just off S coast of Kyushu. Looks very volcanic! :
[link to pbs.twimg.com (secure)]

[link to hisz.rsoe.hu]
Details of Supervolcano
VEI Index: 7
Name: Kikai Caldera
Volcano ID: 0802-06=
Country: JPN
Location: Osumi Islands, Kagoshima Prefecture
Diameter: 150 km�
Last Eruption: ~6,300 years ago
Kikai Caldera is a massive mostly submerged caldera up to 19 kilometres (12 mi) in diameter in the Osumi Islands of Kagoshima prefecture, Japan. It is the remains of the ancient eruption of a gigantic volcano. Kikai Caldera was the source of the Akahoya eruption, one of the largest eruptions during the Holocene (10,000 years ago to present). About 6,300 years ago, pyroclastic flows from that eruption reached the coast of southern Kyushu up to 100 km (62 mi) away, and ash fell as far as Hokkaido. The eruption produced about 150 km3 of tephra, giving it a Volcanic Explosivity Index of 7. Kikai is still an active volcano. Minor eruptions occur frequently on Mount Io, one of the post-caldera subaerial volcanic peaks on Iojima. Iojima is one of three volcanic islands, two of which lie on the caldera rim. The most recent eruptions have occurred in 2004.