Iwakisan

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 40.656°N
  • 140.303°E

  • 1625 m
    5330 ft

  • 283270
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Iwakisan.

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

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

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 AD and have consisted primarily of small-to-moderate phreatic explosions.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1863 Mar 23 Unknown Confirmed 1 Historical Observations
[ 1856 May 20 ] [ Unknown ] Uncertain 2  
[ 1848 Jan 18 ] [ Unknown ] Uncertain 2  
1845 Apr 4 Unknown Confirmed 2 Historical Observations
1844 Apr 7 Unknown Confirmed 2 Historical Observations Summit and south flank?
[ 1833 Apr 11 ] [ Unknown ] Uncertain 2  
[ 1807 Mar 31 ] [ Unknown ] Uncertain 2  
[ 1800 May 11 ] [ Unknown ] Uncertain 2  
[ 1794 Apr 3 ] [ Unknown ] Uncertain 2  
[ 1793 Apr 2 ] [ Unknown ] Uncertain 2  
1790 Oct 9 Unknown Confirmed 2 Historical Observations
[ 1783 Dec 3 ] [ Unknown ] Uncertain 2  
1782 Dec 1 ± 30 days 1783 Mar 12 Confirmed 2 Historical Observations
[ 1782 Apr 12 ] [ Unknown ] Uncertain 2   South flank
[ 1769 ] [ Unknown ] Uncertain 2  
[ 1709 Apr 23 ] [ Unknown ] Uncertain 2  
[ 1694 Jun 19 ] [ Unknown ] Uncertain 2  
[ 1672 Jul 12 ] [ 1672 Jul 28 ] Uncertain 2  
1618 Jan 31 Unknown Confirmed 2 Historical Observations
[ 1605 Apr 10 ] [ Unknown ] Uncertain 2  
1604 Feb 7 Unknown Confirmed 3 Historical Observations Torinoumi
1600 Jul 23 1600 Jul 25 Confirmed 2 Historical Observations Torinoumi
1600 Feb 22 Unknown Confirmed 2 Historical Observations Torinoumi
[ 1597 Jun 13 ] [ Unknown ] Uncertain 2  
[ 1597 Jan ] [ Unknown ] Uncertain 2  
0550 BCE ± 500 years Unknown Confirmed   Tephrochronology Torinoumi lava dome
1050 BCE (?) Unknown Confirmed   Tephrochronology Summit and central lava dome
4050 BCE (?) Unknown Confirmed   Tephrochronology West summit lava dome
8050 BCE (?) Unknown Confirmed   Potassium-Argon Torinoumi lava dome

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
The irregular summit lava dome filling the central crater of Iwaki volcano forms the high point in this view of the SE side of the volcano. Chokai-san is the rounded peak on the left. The summit lava dome is flanked by six explosion craters. Debris-avalanche deposits from repeated collapse of the summit and flanks surround the volcano on all sides. Historical eruptions have been reported since 1597 and have consisted primarily of 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/).
Snow-capped Iwaki stratovolcano rises above farmlands below its SE flank. The peak at the left side of the summit is Chokai-san. Iwaki volcano, symmetrical on all but its western flanks, has been called the Fuji-san of the Tsugaru district. The 2-km-wide summit crater is filled by a lava dome that forms the high point of the volcano. Historical eruptions have been reported since 1597 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/).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

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, http://riodb02.ibase.aist.go.jp/db099/eruption/index.html.

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/.

Volcano Types

Stratovolcano
Lava dome(s)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Andesite / Basaltic Andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
918
13,229
465,065
1,617,801

Affiliated Databases

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).
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).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.