Mt.Ontake, viewed from Kuzo Pass of Route 361 (pictrure: Atsushi Ueda / Wiki Commons)
On-take (御嶽山 Ontake-san) is a massive stratovolcano and the second highest in Japan. It is located at the southern end of the Northern Japan Alps.
Its first historic eruption occurred in 1979. A landslide in 1984 was not related to an eruption and produced a debris avalanche and lahar running down valleys south and east of the volcano.
On-take volcano is one of the holy mountains of Japan and the destination for religious pilgrimage since 1792.
On-take's summit cone was built in a largely buried 4 x 5 km caldera. It lies at the southern end of the Norikura volcanic zone, which extends northward through Norikura volcano to Yake-dake volcano.
The older volcanic complex of Ontake consists of at least 4 major stratovolcanoes that were constructed from about 680,000 to about 420,000 years ago, after which On-take was inactive for more than 300,000 years.
The broad, elongated summit of the younger edifice is cut by a series of small explosion craters along a NNE-trending line. Several phreatic eruptions from On-take post-date the roughly 7300-year-old Akahoya tephra from Kikai caldera.
