Chokaisan
Stratovolcano(es) in Japan
Key Facts
Elevation
2,236 m (7,336 ft)
Type
Stratovolcano(es)
Location
39.099°, 140.049°
Region
Northeast Japan Volcanic Arc
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
Massive Chokaisan volcano is composed of two overlapping stratovolcanoes with a conical profile that inspired the local names of Akita-Fuji or Dewa-Fuji. The summit of the gently sloping western edifice (Nishi-Chokaisan) is cut by a large scarp open to the south that contains lava domes. The younger eastern volcano (Higashi-Chokaisan) began forming about 20,000 years ago, and also has a large scarp, breached to the north.
During an eruption about 2,600 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 eruptions date back to the 6th century CE.
Volcanic Hazards & Risk Assessment
Primary Hazards
Risk Level
Geological Composition & Structure
Rock Types
Tectonic Setting
Age & Formation
Eruption Statistics & Analysis
| Metric | Value | Global Ranking | Significance |
|---|---|---|---|
| Total Recorded Eruptions | Unknown | Low | Moderately active volcano |
| Maximum VEI | VEI Unknown | Minor | Local impact potential |
| Recent Activity | 52 years ago | Historical | Recently active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Northwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 283220
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
Chokaisan is the largest of the NE Honshu volcanoes, seen here from the NE. The volcano is comprised of two main overlapping edifices, the younger eastern area contains the large collapse scarp that was the source of the Kisakata debris avalanche, seen here opening to the N. Smaller cones later filled much of the area near the rear scarp.
Photo courtesy Ichio Moriya (Kanazawa University).
Authority Sources
Related Volcanoes
Basic Information
This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.