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Akita-Komagatake

Photo of this volcano
  • Japan
  • Stratovolcano(es)
  • 1971 CE
  •  
  • Country
  • Primary Volcano Type
  • Last Known Eruption
  •  
  • 39.761°N
  • 140.799°E

  • 1637 m
    5371 ft

  • 283230
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: January 2013 (BGVN 38:01) Citation IconCite this Report

Short lived plume rising to 50 m observed on 14 December 2011

The Japanese Meterological Agency (JMA) reported that a short-lived plume rose to 50 m above Akita-Komaga-take on 14 December 2011 and was recorded by a camera located to the N of Me-dake's summit.

Aerial observations were conducted in cooperation with the Japan Ground Self Defense Force on 13 December. Areas of snow melt corresponded to geothermal areas that had been previously identified. No new geothermal areas were found.

An M 2.6 earthquake on 27 December at 1234 local time occurred ~2 km W of Me-dake, with a maximum JMA Seismic Intensity of 1 in Senboku-city, Akita Prefecture. The JMA Seismic Intensity scale, used in Japan and Taiwan is classified into 10 categories; 0 to 4, 5 weak, 5 strong, 6 weak, 6 strong, and 7. The seismicity around the area had temporarily increased, but then returned to baseline levels. No volcanic activity related to this seismicity was observed.

JMA reported no activity at Akita-Komaga-take in 2012.

Information Contacts: Japan Meteorological Agency (JMA), 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/en).

The Global Volcanism Program has no Weekly Reports available for Akita-Komagatake.

Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

09/1970 (CSLP 85-70) Frequent explosions send ash columns up to 400 m high

10/1970 (CSLP 85-70) As many as 400-500 daily eruptions; continuing as of 8 October

11/1970 (CSLP 85-70) Eruptions with explosion sounds, cinders, and smoke decrease in frequency

12/1970 (CSLP 85-70) Lava flow forms several new arms and is now 600 m long

01/1971 (CSLP 85-70) Explosions at the summit crater and lava flows from a new cinder cone

02/1971 (CSLP 85-70) Explosions decline rapidly and stop in late January

06/1971 (CSLP 85-70) No eruptive activity since 25 January

01/2013 (BGVN 38:01) Short lived plume rising to 50 m observed on 14 December 2011




Information is preliminary and subject to change. All times are local (unless otherwise noted)


September 1970 (CSLP 85-70)

Frequent explosions send ash columns up to 400 m high

Card 1017 (24 September 1970) Frequent explosions send ash columns up to 400 m high

"Akita-Komagatake volcano began a new eruption about 1400 TMT, 18 September. Columns of ash (up to 400m high) were emitted along with rumbling of the ground and drumming of explosion. On 19 September, the volcano was still active. Volcanic ashes and bombs were ejected at intervals of five to ten minutes. Explosions took place every 30 minutes. Occurrence of sulphurous acid gas was detected around the spot."

Information Contacts: Tokiko Tiba, Dept. of Geology, National Science Museum, Tokyo, Japan.


October 1970 (CSLP 85-70)

As many as 400-500 daily eruptions; continuing as of 8 October

Card 1031 (14 October 1970) As many as 400-500 daily eruptions; continuing as of 8 October

Akita-Komagatake volcano began a new eruption on 18 September 1970 and is still active on 8 October. The first eruption with ash columns, explosion sounds, and incandescent cinders was observed at about 2130 JST on 18 September and a small lava flow appeared. The eruption crater is located at the upper flank of Medake, the central cone of this volcano, where weak fumarolic areas appeared about three weeks ago. This is the first eruption since 1932 (phreatic explosion). The crater is 10-15 m in diameter, and explosion smoke including ash and lava blocks went up about 400 m high at intervals of 4-5 minutes, and a 40-70-m-wide lava flow (andesite: by Drs. Aramaki and Ossaka) reached a length of about 600 m from the crater. These Strombolian-type eruptions take place 400-500 times a day and air-shocks caused by explosions are frequently recorded by an installed seismograph. Seismic observation of this volcano has been in operation by JMA, Tohoku University, and Tokyo University, and petrological, geographical, and other geophysical investigations are [conducted] by many volcanologists. No damage is reported.

Information Contacts: Yosihiro Sawada, JMA.


November 1970 (CSLP 85-70)

Eruptions with explosion sounds, cinders, and smoke decrease in frequency

Card 1057 (27 November 1970) Eruptions with explosion sounds, cinders, and smoke decrease in frequency

Strombolian-type eruptions which began at medake in September are still active on 20 November 1970. The lava flow seems to be continuously supplied and was observed to be about 150 m wide and about 600 m long on 4 November. Eruptions with explosion sounds, cinders (about 500 m high, maximum), and volcanic smoke (about 400 m high, maximum) took place 400-500 times per day in the first part of October. This activity became weak in the latter part of the month and the number of eruptions per day was about 200. The rim of the crater at Medake was covered with new cinders or lava blocks, but no other remarkable change was observed.

Information Contacts: Yosihiro Sawada, JMA.


December 1970 (CSLP 85-70)

Lava flow forms several new arms and is now 600 m long

Card 1074 (22 December 1970) Lava flow forms several new arms and is now 600 m long

Explosions at Medake, central cone of this double volcano, began to decrease in number in the middle of October. Explosions took place about 200 times per day with explosions sounds, smoke, and cinders (about 300 m high). But the effusion of new lava did not decline and several new arms of lava flow were formed. Therefore, the lava flow became about 200 m wide and about 600 m long. Volcanic tremors were sometimes recorded by the seismograph installed at a hot-spring spa about 4 km NW of the crater.

Information Contacts: Yosihiro Sawada, JMA.


January 1971 (CSLP 85-70)

Explosions at the summit crater and lava flows from a new cinder cone

Card 1095 (20 January 1971) Explosions at the summit crater and lava flows from a new cinder cone

Strombolian-type volcanic explosions at the summit crater, Medake, have been taking place 100-200 times per day. besides, new lava has been flowing out from the foot of the new cinder cone.

Information Contacts: Yosihiro Sawada, JMA.


February 1971 (CSLP 85-70)

Explosions decline rapidly and stop in late January

Card 1135 (23 February 1971) Explosions decline rapidly and stop in late January

Volcanic explosions at Medake crater had been taking place about 200 times per day until the middle of January 1971. Since the 17th, however, the activity declined rapidly and no volcanic explosion has been recorded by the seismograph installed at a point about 4 km NW of the active crater since 25 January.

Information Contacts: Yosihiro Sawada, JMA.


June 1971 (CSLP 85-70)

No eruptive activity since 25 January

Card 1227 (01 June 1971) No eruptive activity since 25 January

"No eruption has occurred since 25 January this year. It was reported that abnormal phenomena such as explosion sounds, rumbling, etc. were observed in the middle of April, but the information was not confirmed. According to the field observation by the Tazawa-ko Town Office on the 27 April, no active state in and near the crater where volcanic eruptions had taken place until the end of this January was observed, but a weak fumarolic area (about 250 m2) was seen near the crater. Maximum geothermal temperature obtained in this fumarolic area was 80°C. Steaming on the lava flow (about 600 m in length and about 3,600,000 tons in volume) was observed at some places, too.)"

Information Contacts: Seismological Division, JMA.


January 2013 (BGVN 38:01) Citation IconCite this Report

Short lived plume rising to 50 m observed on 14 December 2011

The Japanese Meterological Agency (JMA) reported that a short-lived plume rose to 50 m above Akita-Komaga-take on 14 December 2011 and was recorded by a camera located to the N of Me-dake's summit.

Aerial observations were conducted in cooperation with the Japan Ground Self Defense Force on 13 December. Areas of snow melt corresponded to geothermal areas that had been previously identified. No new geothermal areas were found.

An M 2.6 earthquake on 27 December at 1234 local time occurred ~2 km W of Me-dake, with a maximum JMA Seismic Intensity of 1 in Senboku-city, Akita Prefecture. The JMA Seismic Intensity scale, used in Japan and Taiwan is classified into 10 categories; 0 to 4, 5 weak, 5 strong, 6 weak, 6 strong, and 7. The seismicity around the area had temporarily increased, but then returned to baseline levels. No volcanic activity related to this seismicity was observed.

JMA reported no activity at Akita-Komaga-take in 2012.

Information Contacts: Japan Meteorological Agency (JMA), 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/en).

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 18 confirmed Holocene eruptive periods.

1970 Sep 18 - 1971 Jan 26 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Me-dake
1970 Sep 18 - 1971 Jan 26 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Me-dake

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Ash
   - - - -    - - - - Bombs
1970 Sep 18    - - - - VEI (Explosivity Index)

1932 Jul 21 - 1932 Jul 24 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Ishibora (south flank of Me-dake)
1932 Jul 21 - 1932 Jul 24 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Ishibora (south flank of Me-dake)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Crater Summit.
   - - - -    - - - - Lahar or Mudflow
1932 Jul 21    - - - - VEI (Explosivity Index)

1902 Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode Yoko-dake
1902 - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1 at Yoko-dake

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity Uncertain
   - - - -    - - - - Audible Sounds
1902    - - - - VEI (Explosivity Index)

1890 Dec - 1891 Jan Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode
1890 Dec - 1891 Jan Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Blocks
   - - - -    - - - - Audible Sounds
1890 Dec    - - - - VEI (Explosivity Index)

1100 (?) Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode
1100 (?) - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1100
(?)
   - - - - VEI (Explosivity Index)

0807 (?) Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode AK-1 tephra
0807 (?) - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1 at AK-1 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
0807
(?)
   - - - - VEI (Explosivity Index)

0400 ± 500 years Confirmed Eruption  

Episode 1 | Eruption Episode Me-dake
0400 ± 500 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Me-dake

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Ash

0050 BCE ± 200 years Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode AK-2 tephra
0050 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at AK-2 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
0050 BCE ± 200 years    - - - - VEI (Explosivity Index)

0200 BCE ± 200 years Confirmed Eruption  

Episode 1 | Eruption Episode Minami-dake, Ko-dake
0200 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Minami-dake, Ko-dake

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash

0350 BCE ± 200 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode AK-3 tephra
0350 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at AK-3 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash
   - - - -    - - - - Pumice
0350 BCE ± 200 years    - - - - VEI (Explosivity Index)

1450 BCE ± 50 years Confirmed Eruption  

Episode 1 | Eruption Episode AK-5, AK-4 tephra layers
1450 BCE ± 50 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at AK-5, AK-4 tephra layers

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Pumice

5950 BCE ± 200 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode AK-6 tephra
5950 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at AK-6 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
5950 BCE ± 200 years    - - - - VEI (Explosivity Index)

6150 BCE ± 300 years Confirmed Eruption  

Episode 1 | Eruption Episode
6150 BCE ± 300 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash

6350 BCE ± 200 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode AK-7 tephra
6350 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at AK-7 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
6350 BCE ± 200 years    - - - - VEI (Explosivity Index)

7100 BCE ± 900 years Confirmed Eruption  

Episode 1 | Eruption Episode
7100 BCE ± 900 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Scoria

7850 BCE ± 200 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode AK-8, Horikiri tephra
7850 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 5 Events for Episode 1 at AK-8, Horikiri tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
7850 BCE ± 200 years    - - - - VEI (Explosivity Index)

8300 BCE ± 300 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode AK-9, Arasawa tephra
8300 BCE ± 300 years - Unknown Evidence from Correlation: Tephrochronology

List of 5 Events for Episode 1 at AK-9, Arasawa tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
8300 BCE ± 300 years    - - - - VEI (Explosivity Index)

8800 BCE ± 300 years Confirmed Eruption Max VEI: 3 (?)

Episode 1 | Eruption Episode AK-11, AK-10 tephra layers
8800 BCE ± 300 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at AK-11, AK-10 tephra layers

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
8800 BCE ± 300 years    - - - - VEI (Explosivity Index)
Deformation History

There is data available for 1 deformation periods. Expand each entry for additional details.


Deformation during 2011 Mar 11 - 2011 Mar 11 [Subsidence; Observed by InSAR]

Start Date: 2011 Mar 11 Stop Date: 2011 Mar 11 Direction: Subsidence Method: InSAR
Magnitude: 10.000 cm Spatial Extent: 20.00 km Latitude: 40.000 Longitude: 141.000

Remarks: Subsidence of plutonic bodies triggered by Mw 9.0 Tohoku earthquake

Figure (see Caption)

Close-up interferograms. Blue squares indicate geothermal power plants. GEONET stations are indicated by numbered circles, with the colour inside indicating the GPS displacements in the LOS direction.

From: Takada and Fukushima 2013.


Reference List: Takada and Fukushima 2013; Ozawa and Fujita 2013.

Full References:

Ozawa T, Fujita E, 2013. Local deformations around volcanoes associated with the 2011 off the Pacific coast of Tohoku earthquake. J. Geophys. Res., 118, 390-405. https://doi.org/10.1029/2011JB009129

Takada and Fukushima, 2013. Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan. Nature Geoscience, 6: 637-641.

Emission History

There is no Emissions History data available for Akita-Komagatake.

GVP Map Holdings

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. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.

Smithsonian Sample Collections Database

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

External Sites