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Yokodake

Stratovolcano(es) in Japan

Last Eruption: 1200

Key Facts

Elevation

2,480 m (8,136 ft)

Type

Stratovolcano(es)

Location

36.087°, 138.320°

Region

Northeast Japan Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Yokodake lava dome, capped by eight small craters, has been active into the Holocene. The most recent eruption took place about 800 years ago, when ash emission accompanied emplacement of a small lava flow. Yokodake is at the northern edge of the Kita-Yatsugatake (North Yatsugatake) group of stratovolcanoes and lava domes at the NW end of the NNW-SSE-trending Yatsugatake volcanic massif.

The basaltic-to-dacitic Kita Yatsugatake group also contains the Tateshinayama, Shimagareyama, Chausuyama and Futagomine volcanoes. Tateshinayama is sometimes known as Suwa Fuji because of its conical profile. A large lava flow forms the Tateshina-kogen plateau south of Tateshinayama and Yokodake.

A debris avalanche from edifice collapse in 888 CE created Matsubara Lake on the east side of the massif.

Volcanic Hazards & Risk Assessment

Primary Hazards

    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 Activity826 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: 283031
    • Evidence: Eruption Dated
    • Epoch: Holocene

    About the Photo

    The Kita-Yatsugatake (North Yatsugatake) volcanic group is seen here from the summit of Tengudake to the south. Conical Tateshina (left-center) is a part of a group cones and lava domes at the NW end of the NNW-SSE-trending Yatsugatake volcanic massif. The broad forested slope in the foreground is Nakadake, and the flat-topped peak to the right of Tateshina is Yokodake, which last erupted about 800 years ago.

    Photo by Ichio 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.