Hachijojima
Stratovolcano(es) in Japan
Key Facts
Elevation
854 m (2,802 ft)
Type
Stratovolcano(es)
Location
33.137°, 139.766°
Region
Izu Volcanic Arc
Rock Type
Basalt / Picro-Basalt
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
Hachijojima, in the central Izu Islands about 300 km S of Tokyo, consists of two small Quaternary dominantly basaltic stratovolcanoes forming an elongated NW-SE-trending island. The eroded Pleistocene-to-Holocene Higashiyama volcano occupies the SE end of the 14-km-long island. The symmetrical Holocene Nishiyama volcano the NW end has cones on the SE flank.
The small volcanic island of Kojima lies several kilometers W of Hachijojima. Growth of Higashiyama began several tens of thousands of years ago, and included the formation of two small calderas. The initial submarine and early subaerial eruptions of Nishiyama took place from 10,000 to 8,000 years before present (BP).
Its latest major activity, from the early Holocene until about 4,000 BP, was restricted to flank eruptions. Eruptions recorded since the 15th century have been restricted to the summit of Nishiyama and a submarine vent of unknown location.
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 | 420 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Northwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 284050
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
Nishiyama volcano, seen here from the older Higashiyama, forms the NW part of Hachijojima island. The island's airport and its largest town occupy the flanks. The small volcanic island of Kojima (upper left) lies several kilometers to the west. Major activity from the early Holocene until about 4,000 years ago was restricted to flank eruptions.
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.