🌋VolcanoAtlas

Yoteizan

Stratovolcano in Japan

Last Eruption: -1050

Key Facts

Elevation

1,888 m (6,194 ft)

Type

Stratovolcano

Location

42.827°, 140.812°

Region

Northeast Japan Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Yoteizan is a symmetrical andesitic-to-dacitic stratovolcano with a Fuji-like profile the forms a prominent landmark NW of Toya caldera. Its summit is truncated by a 700-m-wide crater that is cut on its NW rim by overlapping smaller craters. Deep radial gullies cut the flanks.

The latest eruption from the main edifice took place about 5000-6000 years ago. Hangetsu-ko (Half Moon Lake), a tuff cone on the lower NW flank, was estimated from stratigraphic evidence to have erupted about 3000 years ago.

Volcanic Hazards & Risk Assessment

Primary Hazards

  • Pyroclastic flows
  • Lava flows
  • Volcanic bombs and ballistics
  • Lahars and mudflows

Risk Level

Population at RiskHigh
Infrastructure RiskModerate
Aviation RiskSignificant

Geological Composition & Structure

Rock Types

Primary
Andesite / Basaltic Andesite
Silica Content
Intermediate (57-63% SiO₂)

Tectonic Setting

Subduction zone
Formed by oceanic plate subduction, typically producing explosive eruptions due to water-rich magmas.

Age & Formation

Epoch
Holocene
Evidence
Eruption Dated

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity3076 years agoHistoricalHistorically active

Monitoring & Alert Status

Monitoring Networks

Japan Meteorological Agency (JMA)
Real-time seismic monitoring
Geological Survey of Japan
Geochemical monitoring
Global Volcanism Program
International eruption database

Current Status

Normal
No recent activity. Routine monitoring continues.

Nearby Volcanoes in Northwestern Pacific Volcanic Regions

Regional Volcanic Activity
The Northwestern Pacific Volcanic Regions contains multiple active volcanic systems. Cross-regional magma interactions and tectonic stresses can influence eruption patterns across the entire arc. Monitor regional seismic activity and volcanic alerts.

Quick Info

  • Smithsonian ID: 285032
  • Evidence: Eruption Dated
  • Epoch: Holocene

About the Photo

Yoteizan volcano, seen here from the NW, has deep radial valleys and a large crater at the summit with several smaller craters along the NW rim.

Photo by Ichiyo Moriya (Kanazawa University).

Basic Information

This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.