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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 42.827°N
  • 140.811°E

  • 1898 m
    6225 ft

  • 285032
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports for Yoteizan.

The Global Volcanism Program has no Weekly Reports available for Yoteizan.

The Global Volcanism Program has no Bulletin Reports available for Yoteizan.

Basic Data

Volcano Number

Last Known Eruption



1050 BCE

1898 m / 6225 ft


Volcano Types

Pyroclastic cone(s)
Lava dome(s)
Tuff cone

Rock Types

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone
Continental crust (> 25 km)


Within 5 km
Within 10 km
Within 30 km
Within 100 km

Geological Summary

Yoteizan is a symmetrical andesitic-to-dacitic stratovolcano with a Fuji-like profile the forms a prominent landmark NW of Toya caldera. Its 1898-m-high summit, rising about 1500 m above its base, 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.


The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Hayakawa Y, 2009. (pers. comm.).

Japan Meteorological Agency, 2013. National Catalogue of the Active Volcanoes in Japan (fourth edition, English version). Japan Meteorological Agency.

Nakano S, Yamamoto T, Iwaya T, Itoh J, Takada A, 2001-. Quaternary Volcanoes of Japan. Geol Surv Japan, AIST, http://www.aist.go.jp/RIODB/strata/VOL_JP/.

Ono K, Soya T, Mimura K, 1981. Volcanoes of Japan. Geol Surv Japan Map Ser, no 11, 2nd edition, 1:2,000,000.

Eruptive History

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1050 BCE (?) Unknown Confirmed   Tephrochronology NW flank (Hangetsu-ko)
3550 BCE (?) Unknown Confirmed   Tephrochronology

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.




Feature Name Feature Type Elevation Latitude Longitude
Hangetsu-ko Tuff cone

Photo Gallery

Yotei volcano, seen here from the NW, is a symmetrical stratovolcano whose flanks are cut by deep radial valleys. The summit of the 1893-m volcano is truncated by a large crater, which has several subcraters on its NW rim. The age of the last eruption of Yotei volcano is not known.

Photo by Ichiyo Moriya (Kanazawa University).
Symmetrical Yotei volcano towers to the NW above Lake Toya, which fills the 10-km-wide Toya caldera. The caldera was formed during a major eruption about 110,000 years ago. A series of andesitic lava domes in the center of the lake form Nakano-jima island, whose forested slopes appear in the right foreground. The photo was taken from the lower flank of Usu volcano, which was constructed over the southern rim of Toya caldera.

Photo by Norm Banks, 1981 (U.S. Geological Survey).
Shikotsu caldera, seen in an aerial view from the SE with Yotei volcano on the center horizon, is a 13 x 15 km caldera filled by Lake Shikotsu. Following formation of the caldera more than 30,000 years ago, three small stratovolcanoes were constructed along a NW-trending line cutting across the caldera. Snow-capped Tarumai volcano (left center) grew near the SE rim of the caldera, along with Fuppushi volcano to its right. A third volcano, Eniwa, was constructed on the NW caldera rim, at the far side of the lake.

Photo by Ichio Moriya (Kanazawa University).
Yotei volcano is most symmetrical when seen from its western side, as in this view. The deep radial gullies that dissect the slopes of the volcano are less pronounced on this side.

Photo by Shin'ichiro Gomi, 1997 (Hokkaido University).
The Fukidashi lava flow from Yotei volcano in SW Hokkaido descended to the NE foot of the volcano. Vertical cooling joints can be seen at the left in this view near the terminus of the flow. Note the person behind the tree at the lower center for scale.

Photo by Shin'ichiro Gomi, 1997 (Hokkaido University).
Volcanoes and calderas fill much of this NASA Shuttle Radar Tomography (SRTM) image of southern Hokkaido with north to the upper left. Usu volcano (bottom center) lies south of Toya caldera. The smaller caldera to the right along the Pacific Ocean is Kuttara. Tarumai and Eniwa volcanoes lie on the estern and western sides, respectively, of Shikotsu caldera (upper right). The conical white peak at left-center is Yotei volcano; Niseko volcano is along the ridge to its left. The city of Sapporo lies at the base of the mountains (top-center).

NASA Shuttle Radar Tomography Mission image, 2000 (http://earthobservatory.nasa.gov/).

Smithsonian Sample Collections Database

There are no samples for Yoteizan in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites

Large Eruptions of Yoteizan Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
MODVOLC - HIGP MODIS Thermal Alert System Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.
MIROVA Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.