Kozushima
Lava dome(s) in Japan
Key Facts
Elevation
572 m (1,877 ft)
Type
Lava dome(s)
Location
34.219°, 139.153°
Region
Izu Volcanic Arc
Rock Type
Rhyolite
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
A cluster of rhyolitic lava domes and associated pyroclastic deposits form the 4 x 6 km island of Kozushima in the northern Izu Islands. The island is the exposed summit of a larger submarine edifice more than 20 km long that lies along the Zenisu Ridge, one of several en-echelon ridges oriented NE-SW, transverse to the trend of the northern Izu arc. The youngest and largest of the 18 lava domes, Tenjosan, occupies the central portion of the island.
Most of the older domes, some of which are Holocene in age, flank Tenjosan to the north, although late-Pleistocene domes are also found at the southern end of the island. A lava flow may have reached the sea during an eruption in 832 CE. The Tenjosan dome was formed during a major eruption in 838 CE that also produced pyroclastic flows and surges.
Earthquake swarms took place during the 20th century.
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 | 1188 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Northwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 284030
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
The agricultural area on floor of an explosion crater (left) and a flat-topped lava dome (right) are part of Kozushima volcano in the northern Izu Islands. The small 4 x 6 km island formed by a cluster of rhyolitic lava domes and associated pyroclastic deposits. The youngest and largest dome, Tenjoyama, occupies the central portion of the island. Most of the older domes are to the north. Two historical eruptions occurred during the 9th century.
Photo by 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.