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Adatarayama

Photo of this volcano
  • Japan
  • Stratovolcano(es)
  • 1996 CE
  •  
  • Country
  • Primary Volcano Type
  • Last Known Eruption
  •  
  • 37.647°N
  • 140.281°E

  • 1728 m
    5669 ft

  • 283170
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: September 1997 (BGVN 22:09) Citation IconCite this Report

Four hikers killed in a gas-filled depression

Four hikers died from inhalation of volcanic gases after being exposed to fumes on the floor of Numano-taira (also called Numano-daira) crater on 15 September. The hikers were part of a group of 14 Tokyo barbers who became disoriented in foggy conditions and departed from a trail. After three hikers fell at the head of a small valley in the S rim of the crater, another member of the party attempted a rescue but also fell to the floor of the crater, where deadly gases had accumulated due to light northerly winds. Other hikers in the area noticed a strong sulfuric odor, warned others of the danger, and climbed to higher ground. Signs warning of the volcanic gas hazard were posted at the trail head.

According to scientists at the Kusatsu-Shirane Volcano Observatory, fumarolic gas from the SW part of the crater is composed of 0.5% SO2, 60-65% H2S and 33-37% CO2. Gas collected in July from a mud pond on the crater floor contained 41% H2S and 56% CO2. The most likely reason for the fatalities was the presence of the H2S and the calm wind conditions that allowed gases to accumulate in the lowest part of the crater.

The Japan Meteorological Agency (JMA) released a report on recent activity at the volcano including a volcanic gas advisory on 15 September. The report details 5 volcanic earthquakes that occurred in August and increased mud spouting and fumarolic activity. Other activity reported at the crater included mud effusion at three pits on the crater floor in July and August 1996 as well as a very small-scale phreatic explosion on 1 September 1996 (BGVN 21:08).

Information Contacts: Jun-ichi Hirabayashi, Kusatsu-Shirane Volcano Observatory, Tokyo Institute of Technology, Kusatsu, Agatsuma-gun, Gunma 377-17, Japan; Noritake Nishide, Sendai District Meteorological Observatory, Japan Meteorological Agency (JMA), 1-3- 15 Gorin, Miyagino-ku, Sendai 983, Japan; Yoshihisa Kawanabe, Volcanology Section, Environmental Geology Department, Geological Survey of Japan, 1-1-3, Higashi, Tsukuba, Ibaraki, 305 Japan; Tatsuro Chiba, Dept of Disaster Prevention, Asia Air Survey Co., 4-2-18 Shinjuku, Shinjuku-ku, Tokyo 160, Japan (URL: http://www.ajiko.co.jp/en/); Volcano Research Center, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113, Japan (URL: http://www.eri.u-tokyo.ac.jp/VRC/index_E.html).

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

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.

10/1995 (BGVN 20:10) First tremor since 1965

04/1996 (BGVN 21:04) Volcanic tremor detected on four days in April

08/1996 (BGVN 21:08) A small aseismic, phreatic eruption on 1 September

09/1997 (BGVN 22:09) Four hikers killed in a gas-filled depression




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


October 1995 (BGVN 20:10) Citation IconCite this Report

First tremor since 1965

During 27 October, volcanic tremor of about 3-minutes duration was recorded at a site 4.8 km NE of Adatara's summit (station A). This was the first case of tremor since the local observatory began observations in 1965.

Information Contacts: Volcanological Division, Seismological and Volcanological Department, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100 Japan.


April 1996 (BGVN 21:04) Citation IconCite this Report

Volcanic tremor detected on four days in April

On 12, 15, 25, and 26 April, small-amplitude volcanic tremors were detected. Volcanic tremor was previously recorded on 27 October 1995 (BGVN 20:10), the first such occurrence since observations began in 1965.

Information Contacts: Volcanological Division, Seismological and Volcanological Department, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100 Japan.


August 1996 (BGVN 21:08) Citation IconCite this Report

A small aseismic, phreatic eruption on 1 September

A small-scale phreatic eruption suddenly took place on 1 September. On 4 September a survey team from the Japan Meteorological Agency (JMA) verified that mud was sprayed ~100 m from small pits at the summit area (Numanotaira). Mud crusts and mud flows were found around three pits, and a strong odor of sulfurous gas was noted. Some mountaineers witnessed and photographed this eruption. Although both Tohoku University and JMA monitor seismicity of the volcano, no seismic activity was recorded just prior to or during the eruption. After the eruption, there was also no evidence implying an increase in seismicity. This has been the first observation of eruptive phenomena since monitoring began in 1965. Volcanic tremor was last reported in April (BGVN 21:04). The JMA seismic net also recorded volcanic tremor once in June.

A survey by Tatsuro Chiba of Asia Air Survey Co. Ltd. indicated that mud effusion on the Numanotaira crater floor also occurred in July and August of this year. The Asahi TV Company took pictures of mud bubbling in one of the pits during mid-August. According to Tatsuro Chiba, two of three pits in the crater already had existed before 1 September and the third pit might have been formed during the 1 September eruption.

Information Contacts: Volcanological Division, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan; Volcano Research Center, Earthquake Research Institute (ERI), University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan (URL: http://www.eri.u-tokyo.ac.jp/VRC/index_E.html).


September 1997 (BGVN 22:09) Citation IconCite this Report

Four hikers killed in a gas-filled depression

Four hikers died from inhalation of volcanic gases after being exposed to fumes on the floor of Numano-taira (also called Numano-daira) crater on 15 September. The hikers were part of a group of 14 Tokyo barbers who became disoriented in foggy conditions and departed from a trail. After three hikers fell at the head of a small valley in the S rim of the crater, another member of the party attempted a rescue but also fell to the floor of the crater, where deadly gases had accumulated due to light northerly winds. Other hikers in the area noticed a strong sulfuric odor, warned others of the danger, and climbed to higher ground. Signs warning of the volcanic gas hazard were posted at the trail head.

According to scientists at the Kusatsu-Shirane Volcano Observatory, fumarolic gas from the SW part of the crater is composed of 0.5% SO2, 60-65% H2S and 33-37% CO2. Gas collected in July from a mud pond on the crater floor contained 41% H2S and 56% CO2. The most likely reason for the fatalities was the presence of the H2S and the calm wind conditions that allowed gases to accumulate in the lowest part of the crater.

The Japan Meteorological Agency (JMA) released a report on recent activity at the volcano including a volcanic gas advisory on 15 September. The report details 5 volcanic earthquakes that occurred in August and increased mud spouting and fumarolic activity. Other activity reported at the crater included mud effusion at three pits on the crater floor in July and August 1996 as well as a very small-scale phreatic explosion on 1 September 1996 (BGVN 21:08).

Information Contacts: Jun-ichi Hirabayashi, Kusatsu-Shirane Volcano Observatory, Tokyo Institute of Technology, Kusatsu, Agatsuma-gun, Gunma 377-17, Japan; Noritake Nishide, Sendai District Meteorological Observatory, Japan Meteorological Agency (JMA), 1-3- 15 Gorin, Miyagino-ku, Sendai 983, Japan; Yoshihisa Kawanabe, Volcanology Section, Environmental Geology Department, Geological Survey of Japan, 1-1-3, Higashi, Tsukuba, Ibaraki, 305 Japan; Tatsuro Chiba, Dept of Disaster Prevention, Asia Air Survey Co., 4-2-18 Shinjuku, Shinjuku-ku, Tokyo 160, Japan (URL: http://www.ajiko.co.jp/en/); Volcano Research Center, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113, Japan (URL: http://www.eri.u-tokyo.ac.jp/VRC/index_E.html).

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 12 confirmed Holocene eruptive periods.

1996 Sep 1 - 1996 Sep 1 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Numanotaira
1996 Sep 1 - 1996 Sep 1 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Numanotaira

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1996 Sep 1    - - - - VEI (Explosivity Index)
1997 Sep 15    - - - - Fatalities

1900 Jul 17 - 1900 Jul 17 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Numanotaira
1900 Jul 17 - 1900 Jul 17 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Numanotaira

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1900 Jul 17    - - - - Fatalities
1900 Jul 17    - - - - VEI (Explosivity Index)

1899 Aug 24 - 1899 Nov 12 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Numanotaira
1899 Aug 24 - 1899 Nov 12 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Numanotaira

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1899 Aug 24    - - - - VEI (Explosivity Index)

[ 1813 Jan 10 ] Uncertain Eruption

Episode 1 | Eruption Episode Numanotaira
1813 Jan 10 - Unknown Evidence from Unknown

List of 3 Events for Episode 1 at Numanotaira

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity Uncertain
   - - - -    - - - - Volcanic "smoke"
1813 Jan 10    - - - - VEI (Explosivity Index)

0950 ± 50 years Confirmed Eruption  

Episode 1 | Eruption Episode Numanotaira, Ad-p4 tephra
0950 ± 50 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Numanotaira, Ad-p4 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash

0050 BCE ± 900 years Confirmed Eruption  

Episode 1 | Eruption Episode Numanotaira, Ad-p3 tephra
0050 BCE ± 900 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Numanotaira, Ad-p3 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash

0590 BCE ± 200 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT6 tephra
0590 BCE ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Numanotaira, Ad-NT6 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lahar or Mudflow
0590 BCE ± 200 years    - - - - VEI (Explosivity Index)

1550 BCE ± 1100 years Confirmed Eruption  

Episode 1 | Eruption Episode Numanotaira, Ad-p1, p2 tephras
1550 BCE ± 1100 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Numanotaira, Ad-p1, p2 tephras

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash

2600 BCE ± 50 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT5 tephra
2600 BCE ± 50 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Numanotaira, Ad-NT5 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
2600 BCE ± 50 years    - - - - VEI (Explosivity Index)

4300 BCE ± 850 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT4 tephra
4300 BCE ± 850 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at Numanotaira, Ad-NT4 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
4300 BCE ± 1000 years    - - - - VEI (Explosivity Index)

6150 BCE ± 100 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT3 tephra
6150 BCE ± 100 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Numanotaira, Ad-NT3 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
6150 BCE ± 100 years    - - - - VEI (Explosivity Index)

6650 BCE ± 100 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT2 tephra
6650 BCE ± 100 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Numanotaira, Ad-NT2 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
6650 BCE ± 100 years    - - - - VEI (Explosivity Index)

8050 BCE (?) Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Numanotaira, Ad-NT1 tephra
8050 BCE (?) - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at Numanotaira, Ad-NT1 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
8050 BCE
(?)
   - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Adatarayama.

Emission History

There is no Emissions History data available for Adatarayama.

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 Adatarayama in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites