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Shikotsu

Photo of this volcano
  • Japan
  • Caldera
  • 1979 CE
  •  
  • Country
  • Primary Volcano Type
  • Last Known Eruption
  •  
  • 42.688°N
  • 141.38°E

  • 1320 m
    4331 ft

  • 285040
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

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

Tarumai stratovolcano on the caldera's rim is site of 65 earthquakes

The number of volcanic earthquakes beneath Tarumai stratovolcano increased during the second half of August. A total of 65 earthquakes was recorded in August.

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

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

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.

06/1978 (SEAN 03:06) Explosive eruption with small pyroclastic flow after 10 years of increasing seismicity

07/1978 (SEAN 03:07) No new explosions; seismicity declines to normal

12/1978 (SEAN 03:12) Two small ash eruptions

01/1979 (SEAN 04:01) Ash eruptions continue

02/1979 (SEAN 04:02) Small ash eruptions continue; seismicity increases sharply

03/1979 (SEAN 04:03) Small ash eruptions and increased seismicity continue

04/1979 (SEAN 04:04) More ash eruptions but declining seismicity

05/1979 (SEAN 04:05) Seismicity and number of explosions decline

06/1979 (SEAN 04:06) Small ash eruption but decline in seismicity persists

07/1979 (SEAN 04:07) Seismicity increases, but no explosions

08/1979 (SEAN 04:08) No explosions; seismicity declines

11/1979 (SEAN 04:11) Brief increase in seismicity, but no eruption

12/1980 (SEAN 05:12) Seismicity increases

01/1981 (SEAN 06:01) Seismicity continues to increase

02/1981 (SEAN 06:02) Sharp increase in seismicity

03/1981 (SEAN 06:03) Seismicity declines without expected eruption

04/1981 (SEAN 06:04) Minor ash emission during February seismic peak

02/1988 (SEAN 13:02) Earthquake swarms

07/1996 (BGVN 21:07) Seismic activity increases

08/1996 (BGVN 21:08) Tarumai stratovolcano on the caldera's rim is site of 65 earthquakes




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


June 1978 (SEAN 03:06) Citation IconCite this Report

Explosive eruption with small pyroclastic flow after 10 years of increasing seismicity

Tarumai exploded on 14 May at 2253, accompanied by volcanic tremor. A slight ashfall was observed 10 km NNE of the summit crater and a small pyroclastic flow consisting of pumiceous ash and blocks traveled 150 m SE from the vent. Sixteen hours after the eruption, geologists measured a temperature of 200°C at the base of the pyroclastic flow (30 cm below the surface). Smaller explosions occurred on 17 May, mantling the vent area with 1 cm of new ash. No further explosions had been observed as of 7 June.

Tarumai, which last erupted in 1955, is characterized by conspicuous earthquake swarms, followed by explosive eruptions of andesitic magma, then lava dome extrusion. The number of earthquakes at Tarumai has been increasing irregularly for the past 10 years and increased sharply in the first five months of 1978 (figure 1). No eruption was associated with the somewhat smaller peak in seismicity that occurred in 1975.

Figure (see Caption) Figure 1. Monthly seismicity recorded at JMA's Tarumai Observatory, January 1978-June 1979. Arrows represent ash eruptions. Courtesy of JMA.

Further Reference. Katsui, Y., Onuma, K., Niida, K., Suzuki, T., and Kondo, Y., 1979, Eruption of Tarumai volcano in May 1978: Bulletin of the Volcanological Society of Japan, v. 24, no. 2, p. 31-40.

Information Contacts: JMA, Tokyo; D. Shackelford, CA.


July 1978 (SEAN 03:07) Citation IconCite this Report

No new explosions; seismicity declines to normal

As of early July, no eruptive activity had been observed since the explosions of 14 and 17 May. Seismicity decreased to its normal level in mid-June after a 10-year increase preceding the May explosions.

Information Contacts: JMA, Tokyo.


December 1978 (SEAN 03:12) Citation IconCite this Report

Two small ash eruptions

Tarumai erupted ash from 0910 to 0920 on 12 December. The ash cloud rose 200 m above the vent, which was also the source of small explosions on 14 and 17 May. Ash slightly darkened the snow in the summit area, but did not reach the foot of the volcano. A second ash eruption occurred on 16 December, with ashfall again restricted to the summit area. Seismicity remained at a low level (table 1).

Table 1. Monthly seismicity at Shikotsu (Tarumai) in 1978. Courtesy of JMA.

Month Seismic Events
Jan 1978 22
Feb 1978 39
Mar 1978 95
Apr 1978 170
May 1978 298
Jun 1978 112
Jul 1978 26
Aug 1978 18
Sep 1978 13
Oct 1978 17
Nov 1978 13
Dec 1978 [21]

Information Contacts: JMA, Tokyo.


January 1979 (SEAN 04:01) Citation IconCite this Report

Ash eruptions continue

Ash eruptions continued through early January. Ash was ejected on 16, 26, and 29 December and on 5 January, falling on the summit area. Seismicity remained at normal levels through December.

Information Contacts: JMA, Tokyo.


February 1979 (SEAN 04:02) Citation IconCite this Report

Small ash eruptions continue; seismicity increases sharply

Ash eruptions continued through January. Ash was ejected on 5, 22, 23, and 27 January, darkening snow in the summit area, but no ash reached the foot of the volcano.

Local seismicity increased sharply about 10 January, after several months of relative quiet. An irregular increase in seismic activity has persisted since 1967.

Information Contacts: JMA, Tokyo.


March 1979 (SEAN 04:03) Citation IconCite this Report

Small ash eruptions and increased seismicity continue

Ash was ejected on 5, 8, 19, and 25-28 February, continuing the series of small explosions that resumed 12 December. The ash darkened snow in the summit area, but did not reach the foot of the volcano. The number of recorded local earthquakes increased from 201 in January to 427 in February.

Information Contacts: JMA, Tokyo.


April 1979 (SEAN 04:04) Citation IconCite this Report

More ash eruptions but declining seismicity

Ash eruptions continued in March. Ash fell on the summit area on 1, 2, 4, 6, and 8 March but did not reach the foot of the volcano. Seismicity declined considerably in March, but remained slightly above the monthly total for January.

Information Contacts: JMA, Tokyo.


May 1979 (SEAN 04:05) Citation IconCite this Report

Seismicity and number of explosions decline

Eruptive and seismic activity declined substantially in April. Only one [ash eruption] took place in April, on the 13th, causing a small ashfall in the summit area. The monthly number of recorded earthquakes dropped from 223 in March to 70 in April.

Information Contacts: JMA, Tokyo.


June 1979 (SEAN 04:06) Citation IconCite this Report

Small ash eruption but decline in seismicity persists

The decline in activity continued through May. A single small ash eruption occurred in May, on the 11th. Ash fell in the summit area but not reach the foot of the volcano. Monthly recorded earthquakes decreased slightly from 70 in April to 66 in May, but the number of tremor events dropped more sharply, from more than 40 to 9. The tremor events, each lasting a few minutes, were thought to be generated by vigorous activity at a vent. The strongest of this activity was visible from the base of the volcano.

Information Contacts: JMA, Tokyo.


July 1979 (SEAN 04:07) Citation IconCite this Report

Seismicity increases, but no explosions

No explosions or tremor events were recorded in June. However, the number of local earthquakes, which had been declining since March, increased in June.

Information Contacts: JMA, Tokyo.


August 1979 (SEAN 04:08) Citation IconCite this Report

No explosions; seismicity declines

The number of recorded earthquakes declined to 58 in July after rising sharply to 142 in June. No explosions were observed in July, nor were any tremor events, which are presumably generated by [ash ejection].

Information Contacts: JMA, Tokyo.


November 1979 (SEAN 04:11) Citation IconCite this Report

Brief increase in seismicity, but no eruption

An increase in the number of local earthquakes and a resumption of tremor events occurred in mid-September, but no eruption was observed. In October, seismicity returned to normal levels and no tremor events were recorded.

Information Contacts: JMA, Tokyo.


December 1980 (SEAN 05:12) Citation IconCite this Report

Seismicity increases

Seismic activity increased in November after about one and a half years of quiet.

Information Contacts: JMA, Tokyo.


January 1981 (SEAN 06:01) Citation IconCite this Report

Seismicity continues to increase

Seismic activity increased again to more than 400 recorded events during January. No eruption has yet been observed. About 200 events per month were recorded in November and December, after over a year of fewer than 50 events per month.

Information Contacts: JMA, Tokyo.


February 1981 (SEAN 06:02) Citation IconCite this Report

Sharp increase in seismicity

In February, 1,121 seismic events were recorded, the most in any month since 1967, when JMA began routine measurements at the volcano. Seismicity has irregularly but gradually increased in the past 14 years (figure 2). No eruption has occurred during the current increase in seismicity.

Figure (see Caption) Figure 2. Yearly means of Tarumai's monthly seismicity, 1967-80. Courtesy of JMA.

Information Contacts: JMA, Tokyo.


March 1981 (SEAN 06:03) Citation IconCite this Report

Seismicity declines without expected eruption

Local seismicity began to increase in November 1980 and the number of events per month reached 1,211 in February 1981 (figure 3). Seismicity began a gradual decline in early March and by mid-March had reached the usual average of fewer than three recorded earthquakes per day.

Figure (see Caption) Figure 3. Monthly numbers of days with eruptions (top), tremor events (center), and recorded earthquakes (bottom) at Tarumai, January 1978-March 1981. Courtesy of JMA.

Only 87 events were recorded in March. Although the December 1978-May 1979 eruption accompanied the last major increase in seismicity, no eruption has occurred during the current, much larger increase [but see 06:04].

Information Contacts: JMA, Tokyo.


April 1981 (SEAN 06:04) Citation IconCite this Report

Minor ash emission during February seismic peak

Seismicity declined to its usual level of fewer than three recorded earthquakes per day in March and remained at this level through April. Although no volcanic activity apparently had accompanied the peak of seismicity in February (1,211 events), subsequent investigation revealed that a weak steam explosion had occurred on 27 February or a few days earlier.

On the morning of 27 February an All Nippon Airways crew reported that they saw radially darkened snow on the SE part of the summit area. Yoshio Katsui visited the summit on 9 April and found a single layer of gray ash in the snow. The ash layer was only 0.3-0.6 mm thick at the crater rim. The total volume of ejecta was estimated to be no more than 400 m3.

Information Contacts: JMA, Tokyo; Y. Katsui, Hokkaido Univ.


February 1988 (SEAN 13:02) Citation IconCite this Report

Earthquake swarms

Local earthquake swarms occurred 24 January-18 February. The JMA seismometer, 1.1 km NE of the summit cone, recorded 30 events in January and 124 in February. Epicenters were located at the NW somma using data from five Hokkaido University seismometers. A white plume constantly rose ~100 m.

Tarumai's strongest earthquake swarm of the past two decades began in late 1980, peaking in February 1981, when more than 1,200 shocks were recorded. Late that month ~400 m3 of ash was deposited near the crater by a very small eruption. Seismicity then declined, and the number of local events has averaged <10/month in the last few years (figure 4).

Figure (see Caption) Figure 4. Monthly number of earthquakes at Tarumai, January 1967-January 1988. Courtesy of JMA.

Information Contacts: JMA.


July 1996 (BGVN 21:07) Citation IconCite this Report

Seismic activity increases

The number of volcanic earthquakes beneath Tarumai stratovolcano (on the rim on Shikotsu caldera) increased in June and July. There were 13 events on both 8 and 10 June. A total of 64 earthquakes was recorded in July.

Information Contacts: Volcanological Division, Japan Meteorological Agency, 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan


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

Tarumai stratovolcano on the caldera's rim is site of 65 earthquakes

The number of volcanic earthquakes beneath Tarumai stratovolcano increased during the second half of August. A total of 65 earthquakes was recorded in August.

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

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 41 confirmed Holocene eruptive periods.

1981 Feb 27 - 1981 Feb 27 Confirmed Eruption Max VEI: 1

Episode 1 | Phreatic Episode Tarumai
1981 Feb 27 - 1981 Feb 27 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Phreatic activity weak or small
1981 Feb 27    - - - - VEI (Explosivity Index)

1978 Dec 12 - 1979 May 11 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai (SE foot of summit dome)
1978 Dec 12 - 1979 May 11 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Tarumai (SE foot of summit dome)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Ash
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Earthquakes (undefined) After.
1978 Dec 12    - - - - VEI (Explosivity Index)

1978 May 14 - 1978 May 17 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai (SE foot of summit dome)
1978 May 14 - 1978 May 17 Evidence from Observations: Reported

List of 6 Events for Episode 1 at Tarumai (SE foot of summit dome)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Pyroclastic flow weak or small
   - - - -    - - - - Ash
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined)
1978 May 14    - - - - VEI (Explosivity Index)

1954 Nov 19 - 1955 Feb 14 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1954 Nov 19 - 1955 Feb 14 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Ash
   - - - -    - - - - Earthquakes (undefined)
1954 Nov 19    - - - - VEI (Explosivity Index)

1954 May 2 - 1954 May 2 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1954 May 2 - 1954 May 2 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Ash
   - - - -    - - - - Lahar or Mudflow weak or small
1954 May 2    - - - - VEI (Explosivity Index)

1953 Sep 14 (?) - 1953 Sep 14 (?) Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1953 Sep 14 (?) - 1953 Sep 14 (?) Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Ash
1953 Sep 14
(?)
   - - - - VEI (Explosivity Index)

1951 Jul 28 - 1951 Jul 28 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1951 Jul 28 - 1951 Jul 28 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Lahar or Mudflow weak or small
1951 Jul 28    - - - - VEI (Explosivity Index)

1951 Jan 29 - 1951 Jan 29 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1951 Jan 29 - 1951 Jan 29 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Audible Sounds
1951 Jan 29    - - - - VEI (Explosivity Index)

[ 1947 Oct 15 ± 90 days - 1947 Oct 15 ± 90 days ] Uncertain Eruption

Episode 1 | Eruption Episode Tarumai
1947 Oct 15 ± 90 days - 1947 Oct 15 ± 90 days Evidence from Observations: Reported

List of 2 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Volcanic "smoke"
1944 Nov 25    - - - - VEI (Explosivity Index)

1944 Jul 2 - 1944 Jul 2 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1944 Jul 2 - 1944 Jul 2 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Ash
1944 Jul 2    - - - - VEI (Explosivity Index)

1936 Nov 15 - 1936 Nov 26 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1936 Nov 15 - 1936 Nov 26 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
1936 Nov 15    - - - - VEI (Explosivity Index)

1936 Apr 19 - 1936 Apr 19 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1936 Apr 19 - 1936 Apr 19 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1936 Apr 19    - - - - VEI (Explosivity Index)

1933 Dec 1 - 1933 Dec 14 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai (east-west summit fissure)
1933 Dec 1 - 1933 Dec 14 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Tarumai (east-west summit fissure)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Crater Summit.
1933 Dec 1    - - - - VEI (Explosivity Index)

1931 Oct 11 - 1931 Oct 24 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1931 Oct 11 - 1931 Oct 24 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1931 Oct 11    - - - - VEI (Explosivity Index)

1928 Sep 6 - 1929 Feb 10 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1928 Sep 6 - 1929 Feb 10 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1928 Sep 6    - - - - VEI (Explosivity Index)

1928 Jan 7 - 1928 Jan 7 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1928 Jan 7 - 1928 Jan 7 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
1928 Jan 7    - - - - VEI (Explosivity Index)

1926 Oct 19 - 1926 Oct 30 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1926 Oct 19 - 1926 Oct 30 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Lightning
1926 Oct 19    - - - - VEI (Explosivity Index)

1923 Feb - 1923 Aug 23 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1923 Feb - 1923 Aug 23 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1923 Feb    - - - - VEI (Explosivity Index)

1921 Jul 6 - 1921 Jul 6 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1921 Jul 6 - 1921 Jul 6 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1921 Jul 6    - - - - VEI (Explosivity Index)

1920 Jul 17 - 1920 Jul 23 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1920 Jul 17 - 1920 Jul 23 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1920 Jul 17    - - - - VEI (Explosivity Index)

1919 May 4 - 1919 May 4 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1919 May 4 - 1919 May 4 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1919 May 4    - - - - VEI (Explosivity Index)

1918 Jun 13 - 1918 Jul 31 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Tarumai
1918 Jun 13 - 1918 Jul 31 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1918 Jun 13    - - - - VEI (Explosivity Index)

1917 Apr 30 - 1917 May 12 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai (east-west summit fissure)
1917 Apr 30 - 1917 May 12 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai (east-west summit fissure)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Ash
1917 Apr 30    - - - - VEI (Explosivity Index)

1909 Jan 11 - 1909 Apr 22 Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Tarumai
1909 Jan 11 - 1909 Apr 22 Evidence from Observations: Reported

List of 11 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava dome violent, strong, or large
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Blocks
   - - - -    - - - - Incandescence Event was "Glow"
   - - - -    - - - - Lightning
   - - - -    - - - - Earthquakes (undefined)
1909 Jan 11    - - - - VEI (Explosivity Index)
1909 Mar 30    - - - - VEI (Explosivity Index)
1909 Apr 12    - - - - VEI (Explosivity Index)

1894 Aug 17 - 1894 Aug 17 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1894 Aug 17 - 1894 Aug 17 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Earthquakes (undefined) After.
1894 Aug 17    - - - - VEI (Explosivity Index)

1894 Feb 8 - 1894 Feb 8 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1894 Feb 8 - 1894 Feb 8 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
1894 Feb 8    - - - - VEI (Explosivity Index)

1887 Sep 3 - 1887 Oct 8 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1887 Sep 3 - 1887 Oct 8 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Ash
1887 Sep 3    - - - - VEI (Explosivity Index)

1886 Apr 13 - 1886 Apr 28 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1886 Apr 13 - 1886 Apr 28 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Ash
1886 Apr 13    - - - - VEI (Explosivity Index)

1885 Jan 4 - 1885 Mar 26 Confirmed Eruption Max VEI: 2

JMA (2013) described a phreatic summit eruption with ashfall on 4 January 1885, followed by small eruptions on 8 and 10 January. Another summit eruption on 26 March had a volcanic plume "slightly less" than the January activity.

Episode 1 | Eruption Episode Tarumai
1885 Jan 4 - 1885 Jan 10 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
1885 Jan 4    - - - - Explosion moderate
1885 Jan 4    - - - - Ash
1885 Jan 4    - - - - VEI (Explosivity Index)
1885 Jan 8    - - - - Explosion
1885 Jan 10    - - - - Explosion
Episode 2 | Eruption Episode Tarumai
1885 Mar 26 - 1885 Mar 26 Evidence from Observations: Reported

List of 2 Events for Episode 2 at Tarumai

Start Date End Date Event Type Event Remarks
1885 Mar 26    - - - - Explosion
1885 Mar 26    - - - - VEI (Explosivity Index)

1883 Oct 7 - 1883 Nov 5 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1883 Oct 7 - 1883 Nov 5 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Ash
1883 Oct 7    - - - - VEI (Explosivity Index)

1874 Feb 8 - 1874 Feb 16 Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Tarumai
1874 Feb 8 - 1874 Feb 16 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion violent, strong, or large
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
1874 Feb 8    - - - - VEI (Explosivity Index)
1874 Feb 16    - - - - VEI (Explosivity Index)

[ 1871 Dec 25 - 1871 Dec 28 ] Uncertain Eruption

Episode 1 | Eruption Episode Tarumai
1871 Dec 25 - 1871 Dec 28 Evidence from Unknown

List of 3 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
1871 Dec 25    - - - - VEI (Explosivity Index)

1867 Sep 8 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Tarumai
1867 Sep 8 - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
1867 Sep 8    - - - - VEI (Explosivity Index)

1804 - 1817 Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Tarumai
1804 - 1817 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Tarumai

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion violent, strong, or large
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Ash
   - - - -    - - - - Pumice
   - - - -    - - - - Property Damage
1804    - - - - Fatalities
1804    - - - - VEI (Explosivity Index)

1739 Aug 19 - 1739 Aug 31 Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode Tarumai, Ta-a tephra
1739 Aug 19 - 1739 Aug 31 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Tarumai, Ta-a tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion violent, strong, or large
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Pumice
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Caldera Explosion
1739 Aug 19    - - - - VEI (Explosivity Index)

1707 ± 30 years Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Eniwa (crater 3)
1707 ± 30 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Eniwa (crater 3)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lahar or Mudflow
1707 ± 30 years    - - - - VEI (Explosivity Index)

1667 Sep 23 - 1667 Sep 26 (?) Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode Tarumai, Ta-b tephra
1667 Sep 23 - 1667 Sep 26 (?) Evidence from Observations: Reported

List of 6 Events for Episode 1 at Tarumai, Ta-b tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion violent, strong, or large
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
1667 Sep 23    - - - - VEI (Explosivity Index)

1550 ± 75 years Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Eniwa (crater 2)
1550 ± 75 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Eniwa (crater 2)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lahar or Mudflow
1550 ± 75 years    - - - - VEI (Explosivity Index)

1500 ± 150 years Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Eniwa (crater 1)
1500 ± 150 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Eniwa (crater 1)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Avalanche
1500 ± 150 years    - - - - VEI (Explosivity Index)

0050 BCE (?) Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Tarumai, Ta-c3 tephra
0050 BCE (?) - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at Tarumai, Ta-c3 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
0050 BCE
(?)
   - - - - VEI (Explosivity Index)

0100 BCE ± 100 years Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Eniwa volcano (east side of summit)
0100 BCE ± 100 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Eniwa volcano (east side of summit)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
0100 BCE ± 100 years    - - - - VEI (Explosivity Index)

0550 BCE (?) Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode Tarumai, Ta-c1, Ta-c2 tephras
0550 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 5 Events for Episode 1 at Tarumai, Ta-c1, Ta-c2 tephras

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
0550 BCE
(?)
   - - - - VEI (Explosivity Index)

6950 BCE (?) Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode Tarumai, Ta-d tephra
6950 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 5 Events for Episode 1 at Tarumai, Ta-d tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion violent, strong, or large
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
6950 BCE
(?)
   - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Shikotsu.

Emission History

There is no Emissions History data available for Shikotsu.

Photo Gallery

Tarumai volcano, seen here from the SW contains a flat-topped lava dome that formed during an eruption in 1909. The dome was emplaced within a small caldera at the summit that formed during major explosive eruptions in 1667 and 1739 CE.

Photo by Tom Simkin, 1981 (Smithsonian Institution).
The flat-topped lava dome at the summit of Tarumai volcano was formed during an eruption in 1909. Frequent explosive eruptions took place from January 11 until April. On April 19 the new lava dome appeared. The dome grew to a height of 130 m and a width of 450 m. This 1981 photo views the dome from the NE.

Copyrighted photo by Katia and Maurice Krafft, 1981.
A 130-m-high lava dome was emplaced at the summit of Tarumai volcano on Hokkaido in 1909. The dome grew rapidly near the end of an explosive eruption that began on January 1. An eruption in 1917 produced the fissure that cuts diagonally across the dome. Subsequent eruptions have occurred along this fissure and at other locations on the summit and flanks of the dome.

Copyrighted photo by Katia and Maurice Krafft, 1981.
This face-like feature is formed by fissures cutting across a lava dome at the summit of Tarumai volcano on the northern Japanese island of Hokkaido. Two sets of fissures transect the dome, the one trending N30W (lower right) forming the "nose," and the other trending N60E. The lava dome dates to an eruption in 1909. The N60E fissure was formed during an eruption in 1917; later localized eruptions formed the "eyes."

Copyrighted photo by Katia and Maurice Krafft, 1981.
Tarumai volcano was constructed on the SE rim of the 13 x 15 km Shikotsu caldera. The summit has a small 1.5-km-wide caldera that formed during eruptions in 1667 and 1739 CE. It contains a flat-topped summit lava dome that was extruded in 1909. Two other Holocene post-caldera volcanoes occur at Shikotsu, Fuppushi (adjacent to Tarumai) and Eniwa, on the opposite side of the caldera.

Photo by Ichio Moriya (Kanazawa University).
Shikotsu caldera, seen from the SE with Yoteizan volcano on the horizon, is a 13 x 15 km caldera filled by Lake Shikotsu. Following formation of the caldera more than 30,000 years ago, three small cones were constructed along a NW-trend across the caldera. Snow-capped Tarumai (left center) formed near the SE rim of the caldera, along with Fuppushi to its right. A third volcano, Eniwa, was constructed on the NW caldera rim at the far side of the lake.

Photo by Ichio Moriya (Kanazawa University).
These thick pyroclastic flow deposits were produced during the major eruption that formed the 13 x 15 km Shikotsu caldera. The eruption produced 125 km3 of rhyolite tephra and pyroclastic flows. Pyroclastic flows traveled as far as 40 km, reaching the Pacific coast over a broad area. This outcrop is located 15 km ENE of the caldera.

Photo by Ryuta Furukawa, 1993 (Hokkaido University).
The 14 x 12 km Shikotsu caldera is shown in this September 2019 Planet Labs satellite image monthly mosaic (N is at the top; this image is approximately 28 km across). Tarumae is the cone on the SE rim of the caldera with a roughly 1.5-km-wide crater containing a lava dome. Between Tarumae and the caldera lake is the eroded Fuppushi cone. On the opposite (NW) side of the caldera is the Eniwa cone.

Satellite image courtesy of Planet Labs Inc., 2019 (https://www.planet.com/).
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

The following 3 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 101495 Volcanic Rock TARUMAI --
NMNH 111123-1960 Unidentified TARUMAI --
NMNH 91408 Volcanic Bomb TARUMAI --
External Sites