Global Volcanism Program

Iwakisan

Google Earth Placemark with Features

Cite Volcano Profile

Japan
Northeast Japan Volcanic Arc
Composite | Stratovolcano
1863 CE

Country
Volcanic Region
Landform | Volc Type
Last Known Eruption

40.656°N
140.303°E
1,625 m
5,331 ft
283270

Latitude
Longitude
Summit
Elevation
Volcano
Number

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

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

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

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

Tugaru-Huzi | Tsugaru-Fuji | Okuno-Fuji | Asobenomori

Craters

Feature Name

Feature Type

Elevation

Latitude

Longitude

Tanemakishiro
Tanemakisiro

Crater

Torinoumi

Crater

Domes

Feature Name

Feature Type

Elevation

Latitude

Longitude

Iwaki-san

Dome

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

283270

1863 CE

1,625 m / 5,331 ft

40.656°N
140.303°E

Morphology

Volcano Landform
Composite

Volcano Types
Stratovolcano
Lava dome(s)

Rock Types

Major
Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Population

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

918
13,229
465,065
1,617,801

Geological Summary

Iwakisan volcano, symmetrical on all but its western flanks, has been called the Fujisan of the Tsugaru district. The 2-km-wide summit crater is filled by a lava dome flanked by six explosion craters. Three lava domes are found on the western and southern flanks of the andesitic volcano, the NW-most active volcano in Honshu. Historical eruptions have been reported here since 1600 CE and have consisted primarily of small-to-moderate phreatic explosions.

References

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

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.

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.

Kuno H, 1962. Japan, Taiwan and Marianas. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 11: 1-332.

Murayama I, 1987. Volcanoes of Japan (I). Tokyo: Daimedo, 315 p (2nd edition, in Japanese).

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 13 confirmed Holocene eruptive periods.

1863 Mar 23 Confirmed Eruption VEI: 1

Episode 1 | Eruption

1863 Mar 23 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	weak or small
- - - -	- - - -	Blocks
1863 Mar 23	- - - -	VEI (Explosivity Index)

[ 1856 May 20 ] Uncertain Eruption

Episode 1 | Eruption

1856 May 20 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1856 May 20	- - - -	VEI (Explosivity Index)

[ 1848 Jan 18 ] Uncertain Eruption

Episode 1 | Eruption

1848 Jan 18 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	weak or small
	1848 Jan 18	- - - -	VEI (Explosivity Index)

1845 Apr 4 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1845 Apr 4 - Unknown

Evidence from Observations: Reported

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	weak or small
	1845 Apr 4	- - - -	VEI (Explosivity Index)

1844 Apr 7 Confirmed Eruption VEI: 2

Episode 1 | Eruption

Summit and south flank?

1844 Apr 7 - Unknown

Evidence from Observations: Reported

List of 4 Events for Episode 1 at Summit and south flank?

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	weak or small
- - - -	- - - -	Avalanche	Uncertain
- - - -	- - - -	Audible Sounds
1844 Apr 7	- - - -	VEI (Explosivity Index)

[ 1833 Apr 11 ] Uncertain Eruption

Episode 1 | Eruption

1833 Apr 11 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Flames
1833 Apr 11	- - - -	VEI (Explosivity Index)

[ 1807 Mar 31 ] Uncertain Eruption

Episode 1 | Eruption

1807 Mar 31 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Flames
1807 Mar 31	- - - -	VEI (Explosivity Index)

[ 1800 May 11 ] Uncertain Eruption

Episode 1 | Eruption

1800 May 11 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Flames
1800 May 11	- - - -	VEI (Explosivity Index)

[ 1794 Apr 3 ] Uncertain Eruption

Episode 1 | Eruption

1794 Apr 3 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity
	1794 Apr 3	- - - -	VEI (Explosivity Index)

[ 1793 Apr 2 ] Uncertain Eruption

Episode 1 | Eruption

1793 Apr 2 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1793 Apr 2	- - - -	VEI (Explosivity Index)

1790 Oct 9 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1790 Oct 9 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Ash
1790 Oct 9	- - - -	VEI (Explosivity Index)

[ 1783 Dec 3 ] Uncertain Eruption

Episode 1 | Eruption

1783 Dec 3 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1783 Dec 3	- - - -	VEI (Explosivity Index)

1782 Dec 1 ± 30 days - 1783 Mar 12 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1782 Dec 1 ± 30 days - 1783 Mar 12

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Crater	Summit.
1782 Dec 1 ± 30 days	- - - -	VEI (Explosivity Index)

[ 1782 Apr 12 ] Uncertain Eruption

Episode 1 | Eruption

South flank

1782 Apr 12 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1 at South flank

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Volcanic "smoke"
1782 Apr 12	- - - -	VEI (Explosivity Index)

[ 1769 ] Uncertain Eruption

Episode 1 | Eruption

1769 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1769	- - - -	VEI (Explosivity Index)

[ 1709 Apr 23 ] Uncertain Eruption

Episode 1 | Eruption

1709 Apr 23 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1709 Apr 23	- - - -	VEI (Explosivity Index)

[ 1694 Jun 19 ] Uncertain Eruption

Episode 1 | Eruption

1694 Jun 19 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Earthquakes (undefined)
1694 Jun 19	- - - -	VEI (Explosivity Index)

[ 1672 Jul 12 - 1672 Jul 28 ] Uncertain Eruption

Episode 1 | Eruption

1672 Jul 12 - 1672 Jul 28

Evidence from Unknown

List of 4 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Avalanche
- - - -	- - - -	Earthquakes (undefined)
1672 Jul 12	- - - -	VEI (Explosivity Index)

1618 Jan 31 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1618 Jan 31 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Ash
1618 Jan 31	- - - -	VEI (Explosivity Index)

[ 1605 Apr 10 ] Uncertain Eruption

Episode 1 | Eruption

1605 Apr 10 - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity
	1605 Apr 10	- - - -	VEI (Explosivity Index)

1604 Feb 7 Confirmed Eruption VEI: 3 (?)

Episode 1 | Eruption

Torinoumi

1604 Feb 7 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1 at Torinoumi

Start Date	End Date	Event Type
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Lahar or Mudflow
1604 Feb 7	- - - -	VEI (Explosivity Index)

1600 Jul 23 - 1600 Jul 25 Confirmed Eruption VEI: 2

Episode 1 | Eruption

Torinoumi

1600 Jul 23 - 1600 Jul 25

Evidence from Observations: Reported

List of 5 Events for Episode 1 at Torinoumi

Start Date	End Date	Event Type
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Earthquakes (undefined)
- - - -	- - - -	Lahar or Mudflow
- - - -	- - - -	Property Damage
1600 Jul 23	- - - -	VEI (Explosivity Index)

1600 Feb 22 Confirmed Eruption VEI: 2

Episode 1 | Eruption

Torinoumi

1600 Feb 22 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1 at Torinoumi

Start Date	End Date	Event Type
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Lahar or Mudflow
1600 Feb 22	- - - -	VEI (Explosivity Index)

[ 1597 Jun 13 ] Uncertain Eruption

Episode 1 | Eruption

1597 Jun 13 - Unknown

Evidence from Unknown

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity	Uncertain
- - - -	- - - -	Lahar or Mudflow
1597 Jun 13	- - - -	VEI (Explosivity Index)

[ 1597 Jan ] Uncertain Eruption

Episode 1 | Eruption

1597 Jan - Unknown

Evidence from Unknown

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Phreatic activity	Uncertain
	1597 Jan	- - - -	VEI (Explosivity Index)

0550 BCE ± 500 years Confirmed Eruption

Episode 1 | Eruption

Torinoumi lava dome

0550 BCE ± 500 years - Unknown

Evidence from Correlation: Tephrochronology

List of 1 Events for Episode 1 at Torinoumi lava dome

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Lava dome

1050 BCE (?) Confirmed Eruption

Episode 1 | Eruption

Summit and central lava dome

1050 BCE (?) - Unknown

Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at Summit and central lava dome

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Lava dome
- - - -	- - - -	Pumice

4050 BCE (?) Confirmed Eruption

Episode 1 | Eruption

West summit lava dome

4050 BCE (?) - Unknown

Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at West summit lava dome

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Lava dome
- - - -	- - - -	Ash
- - - -	- - - -	Pumice

8050 BCE (?) Confirmed Eruption

Episode 1 | Eruption

Torinoumi lava dome

8050 BCE (?) - Unknown

Evidence from Isotopic: K/Ar

List of 1 Events for Episode 1 at Torinoumi lava dome

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Lava dome

Deformation History

There is no Deformation History data available for Iwakisan.

Emission History

There is no Emissions History data available for Iwakisan.

Photo Gallery

The irregular summit lava dome in the Iwakisan central crater forms the high point in this view from the SE, and has six craters on the flanks. Chokaisan is the rounded peak to the left. Debris avalanche deposits from repeated summit and flank collapse surround the volcano on all sides. Eruptions have been recorded since 1597 CE and have primarily been small-to-moderate phreatic explosions.

Copyrighted photo by Shingo Takeuchi (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/).

Iwakisan rises above farmlands below its SE flank. The peak to the left is Chokaisan and the 2-km-wide summit crater is filled by a lava dome that forms the summit. Eruptions have occurred since 1597 CE and have consisted primarily of small-to-moderate phreatic explosions.

Copyrighted photo by Yoshihiro Ishizuka (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

The following 2 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections, and may be availble for research (contact the Rock and Ore Collections Manager). Catalog number links will open a window with more information.

Catalog Number	Sample Description	Lava Source	Collection Date
NMNH 101496	Unidentified	IWAKI-SAN	--
NMNH 101497	Dacite	IWAKI-SAN	--

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 Iwakisan. 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 Iwakisan. 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 Iwakisan

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).