Kikai Caldera

Kikai Caldera (鬼界カルデラ, Kikai karudera) is a massive, mostly submerged caldera up to 19 kilometres (12 mi) in diameter in the Ōsumi Islands of Kagoshima Prefecture, Japan.

Kikai Caldera
Kikai Caldera Relief Map, SRTM, English.jpg
Highest point
PeakMount Iō (Iōjima),
Iōjima, Ōsumi Islands, Japan
Elevation704 m (2,310 ft)
Coordinates30°47′N 130°19′E / 30.79°N 130.31°E / 30.79; 130.31Coordinates: 30°47′N 130°19′E / 30.79°N 130.31°E / 30.79; 130.31[1]
Length17 km (11 mi) NS
Width20 km (12 mi) EW
Native name鬼界カルデラ
StateKagoshima Prefecture
RegionŌsumi Islands
DistrictKagoshima District
Age of rock6,300 to 95,000 years ago

Kikai Caldera was the source of the Akahoya eruption, the second-largest eruption in recorded history and one of the largest eruptions during the Holocene (10,000 years ago to present). About 6,300 years ago or 4,300 BC, pyroclastic flows from that eruption reached the coast of southern Kyūshū up to 100 km (62 mi) away, and ash fell as far as Hokkaidō. The eruption produced about 150 km³ of tephra,[2] giving it a Volcanic Explosivity Index of 7[3] and making it one of the most explosive in the last 10,000 years, ranking alongside Santorini, Changbaishan, Crater Lake, Kurile Lake and Tambora.[4]

Kikai is still an active volcano. Minor eruptions occur frequently on Mount Iō, one of the post-caldera subaerial volcanic peaks on Iōjima. Iōjima is one of three volcanic islands, two of which lie on the caldera rim. On June 4, 2013, weak tremors were recorded. Shortly after, eruptions began and continued off-and-on for several hours.[5]

Mount Iōdake. May, 2015. Taken from the east.

According to ice cores, the Akahoya eruption may have occurred 4350 BC.[6]

Further readingEdit

  • Machida, Hiroshi; Sugiyama, Shinji (2002). "The impact of the Kikai-Akahoya explosive eruptions on human societies". In Grattan, John; Torrence Robin (eds.). Natural Disasters and Cultural Change. London: Routledge. pp. 313–346. ISBN 0-415-21696-6.

See alsoEdit


  1. ^ "Kikai | Volcano World | Oregon State University". Retrieved 2017-04-11.
  2. ^ Kikai – Eruptive history, Global Volcanism Program. Smithsonian Institution.
  3. ^ Johnston, Eric, "Latest volcano show: Shinmoe", The Japan Times, 1 March 2011, p. 3.
  4. ^ "Large Volcano Explocivity Index". Countries of the World. Retrieved 2014-04-24.
  5. ^ "Global Volcanism Program | Kikai". Retrieved 2017-04-07.
  6. ^ Zielinski, G. A.; Mayewski, P. A.; Meeker, L. D.; Whitlow, S.; Twickler, M. S.; Morrison, M.; Meese, D. A.; Gow, A. J.; Alley, R. B. (1994-05-13). "Record of Volcanism Since 7000 B.C. from the GISP2 Greenland Ice Core and Implications for the Volcano-Climate System". Science. 264 (5161): 948–952. Bibcode:1994Sci...264..948Z. doi:10.1126/science.264.5161.948. ISSN 0036-8075. PMID 17830082.

External linksEdit