Akahoya eruption

Akahoya eruption
Volcano	Kikai Caldera
Date	6,500 years ago
Type	Ultra Plinian
Location	Kyūshū, Japan 30°47′20″N 130°18′29″E / 30.789°N 130.308°E
VEI	7
Impact	One of only six eruptions of its size in the Holocene; dramatically changed vegetation in Southern Kyūshū

The Akahoya eruption was the strongest known volcanic eruption of the Kikai Caldera in Kyūshū, Japan. It ejected about 150 cubic kilometres (36 cu mi) of volcanic material, giving it a 7 on the Volcanic Explosivity Index. The Akahoya eruption is one of only six known eruptions reaching that magnitude during the Holocene, or the last twelve thousand years. It dramatically changed vegetation in Southern Kyūshū.^[1]

Archaeologically it has been dated around 7,300 cal. BP during the Earliest Jōmon period,^[2] but it has also been radiocarbon dated to 6,500 BP.^[3]

References

1. Sugiyama, Shinji (2002). "The Impact of the Kikai-Akahoya Explosive Eruption on Vegetation in Southern Kyushu, Japan, Clarified by Phytolith Studies.". Quaternary Research. 41 (4): 311–316. doi:10.4116/jaqua.41.311. ISSN 0418-2642.
2. Kuwahata, Mitsuhiro (2002). "Age and Cultural Influence of the Kikai-Akahoya Eruption as Seen from Archaeological Material in South Kyushu, Japan". Quaternary Research. 41 (4): 317–330. doi:10.4116/jaqua.41.317. ISSN 0418-2642.
3. Maeno, Fukashi; Taniguchi, Hiromitsu (2005). "Eruptive History of Satsuma Iwo-jima Island, Kikai Caldera, after a 6.5ka Caldera-forming Eruption". Bulletin of the Volcanological Society of Japan. 50 (2): 71–85. ISSN 0453-4360.