No latest activity reported for Chokai.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Ban M, Hayashi S, Takaoka N, 2001. K-Ar dating of the Chokai volcano, northeast Japan arc--a compound volcano composed of continuously established three stratovolcanoes. {Bull Volc Soc Japan (Kazan)}, 46: 317-333 (in Japanese with English abs)

Hasenaka T, Ui T, Nakamura Y, Hayashi S, 1992. Traverse of Quaternary volcanoes in Japan. {29th Internatl Geol Cong, Kyoto, Field Trip A06}, 74 p

Japan Meteorological Agency, 1996. {National Catalogue of the Active Volcanoes in Japan (second edition)}. Tokyo: Japan Meteorological Agency, 502 p (in Japanese)

Kudo T, Hoshizumi H, 2006-. Catalog of eruptive events within the last 10,000 years in Japan, database of Japanese active volcanoes. Geol Surv Japan, AIST, http://riodb02.ibase.aist.go.jp/db099/eruption/index.html

Kuno H, 1962. Japan, Taiwan and Marianas. {Catalog of Active Volcanoes of the World and Solfatara Fields}, Rome: IAVCEI, 11: 1-332

Murayama I, 1987. {Volcanoes of Japan (I)}. Tokyo: Daimedo, 315 p (2nd edition, in Japanese)

Nakano S, Yamamoto T, Iwaya T, Itoh J, Takada A, 2001-. {Quaternary Volcanoes of Japan}. Geol Surv Japan, AIST, http://www.aist.go.jp/RIODB/strata/VOL_JP/

Massive Chokai volcano, the largest of NE Honshu, overlooks the Japan Sea. Chokai is composed of two overlapping stratovolcanoes with a conical profile that has given it the local names Akita-Fuji or Dewa-Fuji. The summit of the gently sloping western volcano (Nishi-Chokai) is cut by a large horseshoe-shaped caldera breached to the south, whose floor contains lava domes. The younger eastern volcano (Higashi-Chokai) began forming about 20,000 years ago. It was cut by another large horseshoe-shaped caldera, breached to the north. During an eruption about 2600 years ago it was the source of the voluminous Kisakata debris avalanche, which reached the Pacific coast. Two post-caldera lava domes have been constructed at the upper SE end of the caldera. Intermittent reports of historical eruptions at Chokai date back to the 6th century AD.