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Akita-Komagatake

Photo of this volcano
  • Japan
  • Japan, Taiwan, Marianas
  • Stratovolcano(es)
  • 1971 CE
  • Country
  • Volcanic Region
  • 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 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1970 Sep 18 1971 Jan 26 Confirmed 2 Historical Observations Me-dake
1932 Jul 21 1932 Jul 24 Confirmed 2 Historical Observations Ishibora (south flank of Me-dake)
1902 Unknown Confirmed 1 Historical Observations Yoko-dake
1890 Dec 1891 Jan Confirmed 2 Historical Observations
1100 (?) Unknown Confirmed 2 Tephrochronology
0807 (?) Unknown Confirmed 3 Historical Observations AK-1 tephra
0400 ± 500 years Unknown Confirmed   Tephrochronology Me-dake
0050 BCE ± 200 years Unknown Confirmed 2 Radiocarbon (corrected) AK-2 tephra
0200 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Minami-dake, Ko-dake
0350 BCE ± 200 years Unknown Confirmed 3 Radiocarbon (corrected) AK-3 tephra
1450 BCE ± 50 years Unknown Confirmed   Radiocarbon (corrected) AK-5, AK-4 tephra layers
5950 BCE ± 200 years Unknown Confirmed 3 Radiocarbon (corrected) AK-6 tephra
6150 BCE ± 300 years Unknown Confirmed   Tephrochronology
6350 BCE ± 200 years Unknown Confirmed 3 Radiocarbon (corrected) AK-7 tephra
7100 BCE ± 900 years Unknown Confirmed   Tephrochronology
7850 BCE ± 200 years Unknown Confirmed 4 Radiocarbon (corrected) AK-8, Horikiri tephra
8300 BCE ± 300 years Unknown Confirmed 4 Tephrochronology AK-9, Arasawa tephra
8800 BCE ± 300 years Unknown Confirmed 3 Tephrochronology AK-11, AK-10 tephra layers
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.

Photo Gallery

Omae-dake cone and the small pond Amida-ike are located at the NE end of the summit crater complex of Akita-Komaga-take volcano. The pyroclastic cone Omae-dake (also known as Komaga-take) forms the highest point of the volcano and has produced lava flows to the north and east. This photo is taken from the NE rim of an elliptical 1.5 x 3 km caldera partially filled by basaltic cones. Historical eruptions have occurred from cones and fissure vents inside the caldera.

Photo by Ichio Moriya (Kanazawa University).
See title for photo information.
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.


Title: Computer Generated Geologic Map of Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1990
Series: No 22
Map Type: Geology
Scale: 1:2,000,000
Map of Computer Generated Geologic Map of Japan

Title: China, Japan, Soviet Union
Publisher: DMA Aerospace Center
Country: Japan, USSR, China
Year: 1988
Series: ONC
Map Type: Topographic
Scale: 1:1,000,000
Map of China, Japan, Soviet Union

Title: Japan, South Korea
Publisher: DMA Aerospace Center
Country: Japan, S Korea
Year: 1988
Series: ONC
Map Type: Topographic
Scale: 1:1,000,000
Map of Japan, South Korea

Title: (A) Q Maps of Japan Landforms, Geol, Tect: NEast
Publisher: Univ of Tokyo Press & Japan Association for Quaternary Research
Country: Japan
Year: 1987
Map Type: Geology
Scale: 1:1,000,000
Map of (A) Q Maps of Japan Landforms, Geol, Tect: NEast

Title: Japan, Soviet Union
Publisher: DMA Aerospace Center
Country: Japan, USSR
Year: 1987
Series: TPC
Map Type: Topographic
Scale: 1:500,000
Map of Japan, Soviet Union

Title: Japan
Publisher: DMA Aerospace Center
Country: Japan
Year: 1985
Series: TPC
Map Type: Topographic
Scale: 1:500,000
Map of Japan

Title: Tayama
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1985
Map Type: Topographic
Scale: 1:50,000
Map of Tayama

Title: Geol Map of Sengan Geothermal Area
Publisher: Geol Survey of Japan
Country: Japan
Year: 1985
Series: USGS-MM
Map Type: Geology
Scale: 1:100,000
Map of Geol Map of Sengan Geothermal Area

Title: Historical Japan
Publisher: National Geographic Society
Country: Japan
Year: 1984
Series: National Geographic
Map Type: Geographic
Scale: 1:2,982,000
Map of Historical Japan

Title: Geol Map of Japan/ Geol Atlas
Publisher: Geol Survey of Japan
Country: Japan
Year: 1982
Map Type: Geology
Scale: 1:1,000,000
Map of Geol Map of Japan/ Geol Atlas

Title: Araya
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1981
Map Type: Topographic
Scale: 1:50,000
Map of Araya

Title: North Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Series: CIM 1:1 mil
Map Type: Topographic
Scale: 1:1,000,000
Map of North Japan

Title: North Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Map Type: Topographic
Scale: 1:1,000,000
Map of North Japan

Title: North Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Map Type: Topographic
Scale: 1:1,000,000
Map of North Japan

Title: Geological Map of Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1978
Map Type: Geology
Scale: 1:1,000,000
Map of Geological Map of Japan

Title: Geological Map of Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1978
Map Type: Geology
Scale: 1:1,000,000
Map of Geological Map of Japan

Title: Numakuni
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1978
Map Type: Topographic
Scale: 1:50,000
Map of Numakuni

Title: Hachimantai
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1975
Map Type: Topographic
Scale: 1:50,000
Map of Hachimantai

Title: Distribution Map of Hot Springs in Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1975
Series: 1:2,000,000
Map Type: Unknown
Scale: 1:2,000,000
Map of Distribution Map of Hot Springs in Japan

Title: (Japanese) Geol map of Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1974
Series: from Natl Atlas Japan
Map Type: Geology
Scale: 1:2,500,000
Map of (Japanese) Geol map of Japan

Title: Landform Classification
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown (Land)
Scale: 1:2,500,000
Map of Landform Classification

Title: Land Use
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown (Land)
Scale: 1:2,500,000
Map of Land Use

Title: Population Distribution
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown
Scale: 1:2,500,000
Map of Population Distribution

Title: River Systems
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown
Scale: 1:2,500,000
Map of River Systems

Title: North Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1966
Map Type: Topographic
Scale: 1:1,000,000
Map of North Japan

Title: Aomori
Publisher: US Army Map Service
Country: Japan
Year: 1955
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Aomori

Title: Hachinohe
Publisher: US Army Map Service
Country: Japan
Year: 1955
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Hachinohe

Title: Akita
Publisher: US Army Map Service
Country: Japan
Year: 1954
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Akita

Title: Moroika
Publisher: US Army Map Service
Country: Japan
Year: 1954
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Moroika

Title: Hachiman-Tai
Publisher: US Army Map Service
Country: Japan
Year: 1944
Series: AMS
Map Type: Topographic
Scale: 1:50,000
Map of Hachiman-Tai

Title: Numakunai
Publisher: US Army Map Service
Country: Japan
Year: 1944
Series: AMS
Map Type: Topographic
Scale: 1:50,000
Map of Numakunai

Title: Araya
Publisher: US Army Map Service
Country: Japan
Year: 1944
Series: AMS
Map Type: Topographic
Scale: 1:50,000
Map of Araya

Title: Sendai
Publisher: US Army Map Service
Country: Japan
Year: 1943
Series: AMS
Map Type: Topographic
Scale: 1:1,000,000
Map of Sendai

Title: Hakodate
Publisher: US Army Map Service
Country: Japan
Year: 1943
Series: AMS
Map Type: Topographic
Scale: 1:1,000,000
Map of Hakodate
Smithsonian Sample Collections Database

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

Affiliated Sites