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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 37.444°N
  • 139.566°E

  • 835 m
    2739 ft

  • 283151
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports for Numazawa.

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

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

Basic Data

Volcano Number

Last Known Eruption



3400 BCE

835 m / 2739 ft


Volcano Types

Lava dome(s)

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

Numazawa is a small, 2-km-wide dominantly dacitic-to-rhyolitic caldera constructed within an older Pliocene caldera. Eruptions of the 110,00 years before present (BP) rhyolitic Shibahara pyroclastic-fall deposit and the 71,000 BP dacitic Mukuresawa lava dome were followed by the dacitic plinian Mizunuma eruption about 45,000 BP, emplacement of the Sozan lava dome at 43,000 BP and the Sozan lava dome at about 20,000 BP. The Numazawako pumice flow and plinian eruption about 4600 years BP resulted in formation of the 1.5 x 2 km Numazawako caldera, now largely filled by a caldera lake.


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

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

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

Kudo T, Hoshizumi H, 2006-. Catalog of eruptive events within the last 10,000 years in Japan, database of Japanese active volcanoes. Geol Surv Japan, AIST,

Nakano S, Yamamoto T, Iwaya T, Itoh J, Takada A, 2001-. Quaternary Volcanoes of Japan. Geol Surv Japan, AIST,

Suzuki T, 1996. Discharge rates of fallout tephra and frequency of plinian eruptions during the last 400,000 years in the southern Northeast Japan arc. Quat Internatl, 34-36: 79-87.

Yagi K, 1971. Some genetic problems of the calderas in Japan. In: Kaloyeropoyloy A (ed) {Acta 1st Internatl Sci Cong on the Volcano of Thera}, Athens: Arch Serv Greece, p 73-87.

Yamamoto T, 1995. Two contrasting styles of pyroclastic flows of Numazawa volcano, NE Japan: stratigraphy of the Numazawako and Mizunuma pyroclastic deposits. Bull Volc Soc Japan (Kazan), 40: 67-81 (in Japanese with English abs).

Yamamoto T, 2007. A rhyolite to dacite sequence of volcanism directly from the heated lower crust: late Pleistocene to Holocene Numazawa caldera. J Volc Geotherm Res, 167: 119-133.

Yamamoto T, 1999. Plinian fall deposits in the Fukushima-Tochigi area during 0.3-0.1 Ma: stratigraphy of marker tephra layers erupting from Numazawa, Hiuchigatake, Kinunuma, and Sunagohara volcanoes. Bull Geol Surv Japan, 50: 743-767.

Eruptive History

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
3400 BCE (?) Unknown Confirmed 5 Radiocarbon (corrected)

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
Numazawako Caldera 835 m 37° 26' 0" N 139° 35' 0" E


Feature Name Feature Type Elevation Latitude Longitude
Dome 835 m
Sozan Dome 815 m

Photo Gallery

Numazawa caldera lake is viewed from its NE shore with a 40,000 year old lava dome forming the right horizon. The 1.5 x 2 km caldera was formed about 5000 years ago during the eruption of the Numazawako Pumice Flow and plinian airfall deposit. The small Numazawa caldera was constructed within an older Pliocene caldera.

Copyrighted photo by Tadahide Ui (Japanese Quaternary Volcanoes database, RIODB, and Geol Surv Japan, AIST,

Smithsonian Sample Collections Database

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

Affiliated Sites

Large Eruptions of Numazawa 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.