Kikai Volcano | John Seach


(Satsuma-Iwo-jima, Tokara-Iwo-Jima)
Ryukyu Islands, Japan

30.78 N, 130.28 E
summit elevation 717 m

Tokara-Iwo-Jima is located 45 km off the south coast of Kyushu. The island is 5.5 x 2.5 km in diamteter, and contains an airstrip, and a population of 140 people on the western end. The island forms the northern edge of the Kikai Caldera. Iwo-dake is a rhyolitic lava dome at the eastern end of Tokara-Iwo-jima, which has produced moderate explosive eruptions over the past few decades.

2020 Eruption
In October 2020  and eruption occurred from the NW caldera rim with ash 200 m above the cratrer.

2019 Eruption
Eruption of Kikai volcano, Satsuma Iojima, Japan on 2 November 2019. Ash emissions reached 6000 ft altitude. Ashfall expected in nearby village of Mishima during the night. Alert level raised to 2 (out of maximum 5).

2013 Eruption
A small ash eruption occurred on 4 June 2013. Ash emissions reached 900 m above the summit.

2004 Eruptions
Small eruptions occurred from Iwo-dake between March to September 2004. Three eruptions produced plumes to 1.5 km altitude.

2003 Eruption
An eruption began at Iwo-dake on 7-8 June 2003 producing plumes to an altitude of 1000 m.

2002 Eruptions
Volcanic tremor began at the volcano on 11th May 2002. Plumes were visible from Satsuma-Iwo-jima during 24-28 May and 1-4 June 2002.

2000-01 Eruptions
Eruptions from Iwo-dake began in October 2000 and continued until December 2001.

1998-99 Eruptions
An eruption occurred at Iwo-dake in late-April or early-May 1998, and deposited 5 cm thick ash around the crater at Iwo-dake dome. Residents of this Tokara-Iwo-Jima witnessed ash falls in August and October 1998. Up to 100 volcanic earthquakes per day were recorded during January and Feburary 1999.

1988 Eruption
In January 1988, renewed eruptions occurred at summit crater of Iwo-dake . Ash was ejected to an altitude of 500 m.

1934-35 Eruption ( 2 km east of Tokara-Iwo-Jima)
Submarine eruptions began 2 kmin September 1934, accompanied by earthquakes. The second phase of the eruption began on 8th December when a pyroclastic cone emerged above the sea level and emitted ‘white smoke’ from its crater. The pyroclastic cone was destroyed by a strong explosion on 30th December. The thirs stage of eruption began in January 1935 with lava flows on the western side of the
islet. This was followed by the formation of a new pyroclastic cone. This was accompanied by accompanied by phreatomagmatic eruptions at intervals of less than a few minutes. In the fourth stage from late January to March, new silicic lava effused, producing a dome.

Eruption in 4300 BC
Kikai was the site of one of the largest eruptions in the world in the past 10,000 years, about 6300 years ago. Pyroclastic flows traveled 100 km across the sea to southern Kyushu, and ash fell in Hokkaido. 1700 km north.

Further Reading
Maeno, F., Imamura, F. and Taniguchi, H., 2006. Numerical simulation of tsunamis generated by caldera collapse during the 7.3 ka Kikai eruption, Kyushu, Japan. Earth, planets and space, 58(8), pp.1013-1024.

Yasuda, Y., 1991. Influences of the vast eruption of Kikai Caldera volcano in the Holocene vegetational history of Yakushima, southern Kyushu, Japan. Nichibunken Japan Review, pp.145-160.

Kikai Volcano Eruptions

2020, 2019, 2013, 2004, 2003, 2002, 2000-01, 1998-99, 1997, 1988, 1934-35, 1914?