Global Volcanism Program

The Global Volcanism Program has no activity reports available for Mashu.

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

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

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.

Synonyms

Masyu

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Kamuinupuri
Mashudake

Stratovolcano

388 m

43° 34' 3" N

144° 33' 19" E

Nishibetsu
Nisibetu

Stratovolcano

797 m

43° 33' 13" N

144° 34' 54" E

Craters

Feature Name

Feature Type

Elevation

Latitude

Longitude

Mashu

Caldera

354 m

43° 34' 50" N

144° 32' 22" E

Domes

Feature Name

Feature Type

Elevation

Latitude

Longitude

Kamuishu
Kamuissyuto
Kamuishuto

Dome

354 m

43° 34' 45" N

144° 31' 39" E

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

285081

1080 CE

857 m / 2,812 ft

43.572°N
144.561°E

Morphology

Volcano Landform
Caldera

Volcano Types
Caldera
Stratovolcano
Lava dome

Rock Types

Major
Andesite / Basaltic Andesite
Dacite
Basalt / Picro-Basalt

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Population

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

9,794
9,794
25,627
632,919

Geological Summary

Mashu is a 6-km-wide Holocene caldera that truncates a stratovolcano constructed on the ESE rim of the large Kussharo caldera. The steep-walled caldera, filled by Lake Mashu, is one of the scenic highlights of Hokkaido. Following caldera collapse about 7,000 years ago, a small andesitic stratovolcano, Kamuinupuri, was formed beginning about 4,000 years ago, creating a reentrant into the SE side of the deep caldera lake. A large explosive eruption about 1,000 years ago, the latest dated eruption, created a 1.2 x 1.5 km crater at the summit of Kamuinupuri. The small island of Kamuishu in the center of Lake Mashu represents the tip of a mostly submerged dacitic lava dome.

References

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, 1975. National Catalogue of the Active Volcanoes in Japan. Tokyo: Japan Meteorological Agency, 119 p (in Japanese).

Japan Meteorological Agency, 1996. National Catalogue of the Active Volcanoes in Japan (second edition). Tokyo: Japan Meteorological Agency, 502 p (in Japanese).

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

Katsui Y, Ando S, Inaba K, 1975. Formation and magmatic evolution of Mashu volcano, east Hokkaido, Japan. Hokkaido Univ Fac Sci Jour, 16: 533-552.

Kishimoto H, Hasegawa T, Nakagawa M, Wada K, 2009. Tephrostratigraphy and eruption style of Mashu volcano, during the last 14,000 years, eastern Hokkaido, Japan. Bull Volc Soc Japan (Kazan), 54: 15-36 (in Japanese with English abs).

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, https://gbank.gsj.jp/volcano/index_e.htm.

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/.

Eruptive History

There is data available for 7 confirmed Holocene eruptive periods.

1080 ± 100 years Confirmed Eruption VEI: 5

Episode 1 | Eruption

Kamuinupuri, Tephra layer Ma-b

1080 ± 100 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Kamuinupuri, Tephra layer Ma-b

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion
- - - -	- - - -	Pumice
- - - -	- - - -	Caldera	Explosion
1080 ± 100 years	- - - -	VEI (Explosivity Index)

0350 ± 100 years Confirmed Eruption VEI: 2

Episode 1 | Eruption

Kamuinupuri, Tephra layer Ma-c1

0350 ± 100 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Kamuinupuri, Tephra layer Ma-c1

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Phreatomagmatic
- - - -	- - - -	Ash
0350 ± 100 years	- - - -	VEI (Explosivity Index)

0150 ± 100 years Confirmed Eruption VEI: 4

Episode 1 | Eruption

Kamuinupuri, Tephra layers Ma-c4-c2

0150 ± 100 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Kamuinupuri, Tephra layers Ma-c4-c2

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Phreatomagmatic
- - - -	- - - -	Ash
0150 ± 100 years	- - - -	VEI (Explosivity Index)

2050 BCE ± 40 years Confirmed Eruption VEI: 4

Episode 1 | Eruption

Kamuinupuri, Tephra layer Ma-d

2050 BCE ± 40 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at Kamuinupuri, Tephra layer Ma-d

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Phreatomagmatic
- - - -	- - - -	Pyroclastic flow
- - - -	- - - -	Pumice
2050 BCE ± 40 years	- - - -	VEI (Explosivity Index)

2800 BCE ± 750 years Confirmed Eruption VEI: 3

Episode 1 | Eruption

Kamuinupuri, Tephra layer Ma-e'

2800 BCE ± 750 years - Unknown

Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Kamuinupuri, Tephra layer Ma-e'

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Phreatomagmatic
- - - -	- - - -	Tephra
2800 BCE ± 1000 years	- - - -	VEI (Explosivity Index)

3550 BCE ± 40 years Confirmed Eruption VEI: 4

Episode 1 | Eruption

Kamuinupuri, Tephra layer Ma-e

3550 BCE ± 40 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at Kamuinupuri, Tephra layer Ma-e

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Phreatomagmatic
- - - -	- - - -	Pyroclastic flow
- - - -	- - - -	Pumice
3550 BCE ± 40 years	- - - -	VEI (Explosivity Index)

5550 BCE ± 100 years Confirmed Eruption VEI: 6

Episode 1 | Eruption

Tephra layers Ma-j-f

5550 BCE ± 100 years - Unknown

Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at Tephra layers Ma-j-f

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion
- - - -	- - - -	Pyroclastic flow
- - - -	- - - -	Pumice	violent, strong, or large
- - - -	- - - -	Caldera	Explosion
5550 BCE ± 100 years	- - - -	VEI (Explosivity Index)

Deformation History

There is no Deformation History data available for Mashu.

Emission History

There is no Emissions History data available for Mashu.

Photo Gallery

Kamuinupuri is a small cone on the SE rim of Mashu caldera. Growth of Kamuinupuri post-dated the roughly 7,000-year-old caldera collapse. The steep scarp below the summit is the NE wall of a 1.2 x 1.5 km caldera that formed at the summit about 1,000 years ago.

Photo by Lee Siebert, 1977 (Smithsonian Institution).

Mashu is a 6-km-wide caldera on the northernmost Japanese island of Hokkaido, seen here from the SW rim with the Kamuishi Island lava dome in the center of the lake. It truncates a stratovolcano on the ESE rim of the larger Kutcharo caldera. The latest eruption of Mashu took place about 1,000 years from Kamuinupuri, the lower flanks of which appear to the far-right.

Photo by Lee Siebert, 1977 (Smithsonian Institution).

The deep blue waters of 6-km-wide Mashu caldera are seen here from its western rim. The small island of Kamuishu in the center of Lake Mashu (right-center) is the tip of a mostly submerged lava dome. Mashu is a Holocene caldera of a volcano constructed on the ESE rim of the Kussharo caldera. Following caldera collapse, Kamuinupuri (whose lower flanks are visible at the far right) formed beginning about 4,000 years ago.

Copyrighted photo by Shun Nakano, 2001 (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

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

External Sites

Copernicus Browser

The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions.

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.

MODVOLC Thermal Alerts

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.

WOVOdat
   Single Volcano View
   Temporal Evolution of Unrest
   Side by Side Volcanoes

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.

GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments.

Volcanic Hazard Maps

The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter.

IRIS seismic stations/networks

Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of Mashu. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice.

UNAVCO GPS/GNSS stations

Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of Mashu. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player.

DECADE Data

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO₂ to the atmosphere, but installing CO₂ monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

Large Eruptions of Mashu

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).

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).