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Iwakisan

Photo of this volcano
  • 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.

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 Event Remarks
   - - - -    - - - - 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 Event Remarks
   - - - -    - - - - 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 Event Remarks
   - - - -    - - - - 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 Event Remarks
   - - - -    - - - - 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 Event Remarks
   - - - -    - - - - 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 Event Remarks
   - - - -    - - - - 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.

GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

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