🌋VolcanoAtlas

Hakoneyama

Complex in Japan

Last Eruption: 2015

Key Facts

Elevation

1,438 m (4,718 ft)

Type

Complex

Location

35.233°, 139.021°

Region

Izu Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Hakoneyama volcano is truncated by two overlapping calderas, the largest of which is 10 x 11 km wide. The calderas were formed as a result of two major explosive eruptions about 180,000 and 49,000-60,000 years ago. Scenic Lake Ashi lies between the SW caldera wall and a half dozen post-caldera lava domes that were constructed along a NW-SE trend cutting through the center of the calderas.

Dome growth occurred progressively to the NW, and the largest and youngest of these, Kamiyama, forms the high point. The calderas are breached to the east by the Hayakawa canyon. A phreatic explosion about 3000 years ago was followed by collapse of the NW side of Kamiyama, damming the Hayakawa valley and creating Lake Ashi.

The latest magmatic eruptive activity about 2900 years ago produced a pyroclastic flow and a lava dome in the explosion crater, although phreatic eruptions took place as recently as the 12-13th centuries CE. Seismic swarms have occurred during the 20th century. Lake Ashi, along with the thermal areas in the caldera, is a popular resort destination SW of Tokyo.

Volcanic Hazards & Risk Assessment

Primary Hazards

    Risk Level

    Population at RiskHigh
    Infrastructure RiskHigh
    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 Activity11 years agoRecentRecently 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

    Watch
    Dormant but monitored. Capable of renewed activity.

    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: 283020
    • Evidence: Eruption Dated
    • Epoch: Holocene

    About the Photo

    Lake Ashi, seen here from the SE, occupies the SW corner of Hakone caldera. Hakoneyama contains two calderas, the largest of which is 10 x 11 km. The arcuate caldera rim is to the left and the flanks of a group of post-caldera cones form the right-hand shoreline. Post-caldera eruptions have constructed a half dozen lava domes along a SW-NE trend across the center of the calderas. An eruption took place around 3,000 years ago and seismic swarms occurred frequently during the 20th century.

    Photo by Lee Siebert, 1963 (Smithsonian Institution).

    Basic Information

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