Report on Suwanosejima (Japan) — September 1976
Natural Science Event Bulletin, vol. 1, no. 12 (September 1976)
Managing Editor: David Squires.
Suwanosejima (Japan) Pilots note unusually high "smoke" columns
Please cite this report as:
Global Volcanism Program, 1976. Report on Suwanosejima (Japan) (Squires, D., ed.). Natural Science Event Bulletin, 1:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197609-282030
Suwanosejima
Japan
29.638°N, 129.714°E; summit elev. 796 m
All times are local (unless otherwise noted)
TOA (domestic) airline pilots noted unusually high "smoke" columns from On-take summit crater in July (table 1). [This crater name, used in original SEAN reports (and Volcanoes of the World), should not be confused with the volcano of the same name on Honshu.]
Table 1. Summary of explosions and other observations from Suwanose-jima, October 1975-December 1985. White vapor was emitted during days not listed in the table for 1977-78. "NVO" for 1979-October 1982 data indicates no visual observation due to bad weather. Numbers in parentheses are the local observation times. Dashes indicate no data provided or unknown. Data have been combined from monthly Bulletin tables and JMA has added data missing from original reports, including May 1984 and 1985. Courtesy of JMA.
| Date | Time Period | Plume Height (m) | Activity |
| 04 Oct 1975 | -- | 700 | Sometimes moderate explosions |
| 05 Oct 1975 | -- | 1000 | Sometimes large explosions, ashfall |
| 06 Oct 1975 | -- | 1500 | Large explosions, ashfall |
| 07 Oct 1975 | -- | -- | Explosion |
| 08 Oct 1975 | -- | 1000 | Large explosion |
| 09 Oct 1975 | -- | 500 | Explosion |
| 09 Nov 1975 | -- | 1500 | Large explosion |
| 10 Nov 1975 | -- | 600 | Explosion |
| 19 Nov 1975 | -- | 500 | Large explosion |
| 07 Dec 1975 | -- | 200 | Sometimes small explosions |
| 21 Dec 1975 | -- | 700 | Frequent large explosions |
| 21 Dec 1975 | -- | 400 | Remarkable incandescent column, frequent large explosions |
| 23 Dec 1975 | -- | 700 | Explosion |
| 24 Dec 1975 | -- | 400 | Sometimes large explosions |
| 25 Dec 1975 | -- | 700 | Explosion |
| 26 Dec 1975 | -- | 1000 | Frequent large explosions |
| 27 Dec 1975 | -- | 700 | Large explosion |
| 28 Dec 1975 | -- | 700 | Moderate explosion |
| 31 Dec 1975 | -- | 400 | -- |
| 08 Jan 1976 | -- | 300 | Large explosion |
| 24 Jan 1976 | -- | 1000 | Ashfall |
| 25 Jan 1976 | -- | 1000 | Large explosion, ashfall |
| 26 Jan 1976 | -- | -- | Ashfall |
| 27 Jan 1976 | -- | 500 | Large explosion, ashfall |
| 28-29 Jan 1976 | -- | 1500 | -- |
| 14 Feb 1976 | -- | -- | Moderate explosion |
| 15 Feb 1976 | -- | 800 | Moderate explosion, ashfall |
| 16 Feb 1976 | -- | -- | Sometimes explosion sounds, ashfall |
| 17 Feb 1976 | -- | -- | Sometimes explosion sounds |
| 18 Feb 1976 | -- | 300 | Sometimes explosion sounds |
| 19 Feb 1976 | -- | 700 | Explosion |
| 20 Feb 1976 | -- | 500 | Moderate explosion |
| 26 Feb 1976 | -- | -- | Explosion |
| 12 Mar 1976 | -- | 500 | Frequent large explosions |
| 13 Mar 1976 | -- | 700 | Frequent large detonations |
| 14 Mar 1976 | -- | 500 | Sometimes moderate explosions |
| 13 Apr 1976 | -- | -- | Moderate detonation |
| 14 Apr 1976 | -- | 300 | Ashfall |
| 15 Apr 1976 | -- | 300 | Ashfall, moderate explosion |
| 16 Apr 1976 | -- | 1000 | Ashfall |
| 10 May 1976 | -- | 500 | Explosion |
| 03 Jul 1976 | -- | 4200 | Moderate detonation |
| 04 Jul 1976 | -- | 3600-4200 | TOA airline pilot observed ashcloud |
| 07 Jul 1976 | -- | 3600 | TOA airline pilot observed ashcloud |
| 23 Jul 1976 | -- | 3000 | Explosion, large ash cloud, ashfall |
| 24 Jul 1976 | -- | 3000 | Explosion, ashfall |
| 04 Oct 1976 | -- | 500 | Ashfall |
| 12 Oct 1976 | -- | 500 | Ashfall |
| 01 Nov 1976 | -- | -- | Ashfall |
| 11 Jan 1977 | -- | 1200 | One explosion |
| 19-21 Mar 1977 | -- | 700 | Ash ejection and ashfall |
| 24-25 Mar 1977 | -- | -- | Two explosions |
| 01-03 Apr 1977 | -- | 1000 | One explosion, ash ejections |
| 10-11 Apr 1977 | -- | 3000 | Ash ejections and ashfall |
| 14-20 Apr 1977 | -- | 1000 | Two explosions, ash ejections and ashfall |
| 27-29 Apr 1977 | -- | 3000 | Explosions, ash ejections |
| 08 May 1977 | -- | -- | One explosion |
| 13-18 May 1977 | -- | 2000 | Several explosions, ashfall |
| 26 May 1977 | -- | 1000 | One explosion |
| 03-05 Jun 1977 | -- | 3000 | Frequent explosions, incandescent column, ashfall |
| 21-22 Jun 1977 | -- | 3000 | Frequent explosions |
| 09-10 Jul 1977 | -- | 4000 | Ash ejections, one explosion |
| 23 Jul 1977 | -- | -- | Explosions |
| 08-10 Aug 1977 | -- | 3000 | Frequent explosions, incandescent ejecta |
| 10-15 Sep 1977 | -- | 3000 | Frequent explosions, ash ejections, ashfall |
| 18 Sep 1977 | -- | 3000 | Ash ejections and ashfall |
| 23 Oct 1977 | -- | 1000 | One ash ejection |
| 26-30 Oct 1977 | -- | 2000 | Ash ejections |
| 14 Nov 1977 | -- | -- | One explosion |
| 19 Nov 1977 | -- | 2000 | Ash ejections |
| 06 Dec 1977 | -- | -- | One explosion |
| 23 Jan 1978 | -- | -- | Three explosions |
| 19 Mar 1978 | -- | 500 | Two ash ejections |
| 22-25 Mar 1978 | -- | 1000 | Ash ejections |
| 09 Apr 1978 | -- | 1000 | Ash ejections |
| 19-22 Apr 1978 | -- | 3000 | Ash ejections and ashfall |
| 01-03 May 1978 | -- | 500 | Ash ejections and ashfall |
| 31 May 1978 | -- | 500 | Frequent explosions, incandescent column |
| 01 Jun 1978 | -- | 500 | Frequent explosions, incandescent column, ashfall |
| 16-19 Jun 1978 | -- | -- | Frequent explosions |
| 02-05 Jul 1978 | -- | 700 | Frequent explosions, incandescent column, ashfall |
| 19-21 Jul 1978 | -- | 3000 | Ash ejections and ashfall |
| 07-10 Aug 1978 | -- | 3000 | Frequent explosions, incandescent column, ashfall |
| 24 Aug 1978 | -- | 2000 | Ash ejections and ashfall |
| 07 Sep 1978 | -- | 3000 | Frequent explosions, ashfall |
| 17 Sep 1978 | -- | -- | One explosion |
| 23-24 Sep 1978 | -- | 700 | Frequent explosions, incandescence |
| 10-12 Oct 1978 | -- | 5000 | Frequent explosions, ashfall |
| 24-28 Oct 1978 | -- | 3000 | Frequent explosions, incandescence, ashfall |
| 06-10 Nov 1978 | -- | 700 | Explosions, incandescence, ashfall |
| 19-22 Nov 1978 | -- | 500 | Explosions, incandescent column, ashfall |
| 04-05 Dec 1978 | -- | 300 | Explosions |
| 06 Feb 1979 | -- | 500 | Explosions, incandescence |
| 14-15 Feb 1979 | -- | 500 | Explosions, ashfall |
| 19 Feb 1979 | -- | 500 | One explosion |
| 22 Feb 1979 | -- | -- | One explosion |
| 11-13 Mar 1979 | -- | 500 | Four explosions |
| 05 Jun 1979 | -- | -- | Incandescent column, explosions |
| 20 Jul 1979 | -- | 500 | Seven explosions, ash emissions |
| 21 Jul 1979 | -- | 200 | Ash emissions |
| 05-06 Sep 1979 | -- | 2000 | Frequent, strong explosions, incandescent columns, ashfall to sea |
| 07 Sep 1979 | -- | 1000 | Ash emissions |
| 08 Sep 1979 | -- | 800 | Ash emissions |
| 09 Sep 1979 | -- | 2000 | Frequent explosions |
| 12 Sep 1979 | -- | 1000 | Ten explosions |
| 10 Dec 1979 | -- | 1500 | Explosions, incandescent blocks, reflected glow |
| 11 Dec 1979 | -- | -- | Ash emissions |
| 12 Dec 1979 | -- | -- | "Flames" in crater |
| 18 Dec 1979 | -- | 300 | Three explosions |
| 05-06 Feb 1980 | -- | 1500 | About 10 explosions, incandescent column |
| 21-22 Mar 1980 | -- | 1000 | Many explosions |
| 25-26 Apr 1980 | -- | 1500 | Explosions: ashfall on inhabited areas |
| 13 May 1980 | -- | -- | Three explosions |
| 18 May 1980 | -- | 500 | Six explosions; persistent ash ejection |
| 04-05 Jun 1980 | -- | 500 | More than 25 explosions |
| 16-19 Jul 1980 | -- | -- | Many explosions |
| 03-08 Aug 1980 | -- | 1500 | Several tens of explosions; incandescent column |
| 21-23 Aug 1980 | -- | 1000 | More than 20 explosions; incandescent column |
| 08-09 Sep 1980 | -- | 1000 | More than 1000 explosions |
| 20 Sep 1980 | -- | -- | Three explosions |
| 24-27 Sep 1980 | -- | 2000 | More than 1000 explosions |
| 25-27 Oct 1980 | -- | 500 | Persistent ash ejection |
| 08-10 Nov 1980 | -- | 1500 | More than 1000 explosions |
| 29 Nov 1980 | -- | 500 | Persistent ash ejection |
| 13 Dec 1980 | -- | -- | Explosions |
| 04-08 Jan 1981 | -- | 100-1000 | Continuous ash cloud |
| 29 Jan 1981 | -- | 500 | Ten explosions |
| 30 Jan 1981 | -- | 300 | Two explosions |
| 31 Jan 1981 | -- | NVO | Two explosions |
| 12 Feb 1981 | -- | 1000 | One explosions |
| 20 Feb 1981 | -- | 1000 | Three explosions |
| 26 Feb 1981 | -- | 500 | 16 explosions |
| 17 Mar 1981 | -- | 1000 | 20 explosions |
| 15 Apr 1981 | -- | NVO | Many explosions |
| 16 Apr 1981 | -- | NVO | 16 explosions |
| 26 Apr 1981 | -- | 500 | Many explosions |
| 14 May 1981 | -- | 500 | Ten explosions |
| 12 Jun 1981 | -- | 1500 | Three explosions |
| 13 Jun 1981 | -- | NVO | Two explosions |
| 15 Jun 1981 | -- | NVO | Three explosions |
| 16 Jun 1981 | -- | NVO | Three explosions |
| 29-30 Jun 1981 | -- | -- | Many explosions |
| 01-04 Jul 1981 | -- | NVO | Many explosions |
| 05 Jul 1981 | -- | 500 | Ten explosions |
| 06 Jul 1981 | -- | NVO | Ten explosions |
| 13 Jul 1981 | -- | NVO | Three explosions |
| 14 Jul 1981 | -- | 2000 | Many explosions |
| 15 Jul 1981 | -- | NVO | Six explosions |
| 26 Nov 1981 | -- | NVO | Many explosions |
| 27 Nov 1981 | -- | 1500 | Many explosions |
| 13 Dec 1981 | -- | 500 | 40-50 explosions; rumbling |
| 14 Dec 1981 | -- | 500 | Many explosions; rumbling |
| 15 Dec 1981 | -- | 500 | 30-40 explosions; rumbling |
| 16 Dec 1981 | -- | 500 | Two explosions |
| 23 Dec 1981 | -- | NVO | Two explosions |
| 02 Jan 1982 | -- | 1500 | Four explosions |
| 23 Jan 1982 | -- | 1000 | 2-3 explosions/hour |
| 25 Jan 1982 | -- | 200 | Ten explosions |
| 26 Jan 1982 | -- | 500 | Many explosions |
| 27 Jan 1982 | -- | 300 | 12 explosions |
| 28 Jan 1982 | -- | 300 | Three explosions |
| 03 Feb 1982 | -- | NVO | Five explosions |
| 06 Feb 1982 | -- | 200 | Five explosions |
| 07 Feb 1982 | -- | 200 | One explosion |
| 08 Feb 1982 | -- | 200 | One explosion |
| 13 Feb 1982 | -- | 1000 | One explosion; rumbling |
| 14-15 Feb 1982 | -- | 500 | Many explosions; rumbling |
| 16-17 Feb 1982 | -- | NVO | Many explosions; rumbling |
| 18 Feb 1982 | -- | 500 | Many explosions; rumbling |
| 19 Feb 1982 | -- | NVO | Six explosions |
| 22 Feb 1982 | -- | 1000 | Three explosions |
| 23 Feb 1982 | -- | NVO | Four explosions |
| 24 Feb 1982 | -- | NVO | Three explosions |
| 25 Feb 1982 | -- | 1000 | Seven explosions; rumbling |
| 26 Feb 1982 | -- | 500 | Five explosions |
| 09 Mar 1982 | -- | 1000 | Many explosions; rumbling |
| 10 Mar 1982 | -- | 1000 | Many explosions; rumbling |
| 11 Mar 1982 | -- | 500 | Ten explosions |
| 28 Mar 1982 | -- | NVO | Ten explosions; rumbling |
| 29 Mar 1982 | -- | NVO | 20-25 explosions; rumbling |
| 30 Mar 1982 | -- | 1000 | Four explosions |
| 31 Mar 1982 | -- | NVO | Six explosions |
| 01 Apr 1982 | -- | 1000 | Two explosions |
| 02 Apr 1982 | -- | 1000 | Ten explosions |
| 03 Apr 1982 | -- | NVO | Three explosions |
| 15 Apr 1982 | -- | 500 | 18-20 explosions; rumbling |
| 17 Apr 1982 | -- | 500 | 5-6 explosions/hour |
| 18 Apr 1982 | -- | NVO | 2-3 explosions/hour |
| 19 Apr 1982 | -- | NVO | Ten explosions; rumbling |
| 05 May 1982 | -- | 200 | One explosion |
| 06 May 1982 | -- | 1000 | Many explosions; rumbling |
| 27 May 1982 | -- | 1000 | One explosion |
| Jun-Jul 1982 | -- | NVO | Quiet |
| 16 Aug 1982 | -- | 1000 | Four explosions |
| 17 Aug 1982 | -- | 500 | Four explosions |
| 02 Sep 1982 | -- | 500 | Five explosions |
| 16 Sep 1982 | -- | NVO | Many explosions |
| 25 Sep 1982 | -- | 200 | Nine explosions |
| 26 Sep 1982 | -- | 200 | Three explosions |
| 05 Oct 1982 | -- | 500 | Three explosions; rumbling |
| 06 Oct 1982 | -- | NVO | Six explosions |
| 07 Oct 1982 | -- | NVO | Seven explosions |
| 08 Oct 1982 | -- | NVO | Ten explosions; rumbling |
| 09 Oct 1982 | -- | 300 | Seven explosions |
| 17 Oct 1982 | -- | NVO | One explosion |
| 03 Nov 1982 | 0500-2200 LT | 500 | 3-4 explosions/hour |
| 04 Nov 1982 | 0500-2200 LT | 500 | 5-6 explosions/hour |
| 05 Nov 1982 | 0700-2100 LT | 500 | 5-6 explosions/hour |
| 06 Nov 1982 | 0500-2200 LT | 500 | 3 explosions/hour |
| 07 Nov 1982 | 0500-2200 LT | 500 | 1-2 explosions/hour |
| 23 Nov 1982 | 0900-1300 LT | 500 | Five explosions |
| 15 Dec 1982 | -- | 500 | Ashfall |
| 17 Dec 1982 | 1300-2000 LT | 1000 | 15-16 explosions |
| 18 Dec 1982 | -- | 500 | Ashfall |
| 19 Dec 1982 | 0900-2100 LT | 1000 | 2-3 explosions/minute |
| 20 Dec 1982 | 0600-2100 LT | 1000 | 1-2 explosions/5 minutes |
| 29 Dec 1982 | 1000-1300 LT | 500 | Two explosions |
| 17 Jan 1983 | 0630-0800 LT | 500 | 4-6 explosions/minute |
| 17 Jan 1983 | 0800-2000 LT | -- | 3-4 explosions/hour |
| 18 Jan 1983 | 0600-2200 LT | Unknown | 3-5 explosions/hour |
| 19 Jan 1983 | 0600-1700 LT | Unknown | 15-20 explosions |
| 28 Jan 1983 | 1700-2200 LT | 500 | 25-30 explosions |
| 29 Jan 1983 | 0500-1800 LT | 700 | 2-3 explosions/minute |
| 29 Jan 1983 | 1800-2200 LT | -- | 4-5 explosions/hour |
| 30 Jan 1983 | 0500-1600 LT | 1000 | 4-5 explosions/hour |
| 10 Feb 1983 | -- | 200 | A few explosions |
| 11 Feb 1983 | 1900-2100 LT | 500 | 1-2 explosions/minute |
| 26 Feb 1983 | 1530-2300 LT | 1000 | 5-6 explosions/minute |
| 27 Feb 1983 | 0500-1200 LT | 1000 | Ten explosions |
| 04 Mar 1983 | -- | Unknown | One explosion |
| 11 Mar 1983 | 1400-2300 LT | 1000 | 2-3 explosions/minute |
| 12 Mar 1983 | 0600-1200 LT | Unknown | 12 explosions |
| 13 Mar 1983 | 0800-1200 LT | -- | Three explosions |
| 28 Apr 1983 | 1400-1600 LT | Unknown | 3-5 explosions/minute |
| 29 Apr 1983 | 1500-1900 LT | 500 | Three explosions |
| 08 May 1983 | 0700-1500 LT | 200 | Six explosions |
| 11 May 1983 | 1400-1500 LT | 200 | Three explosions |
| 12 May 1983 | 1300-1500 LT | 200 | Three explosions |
| 08 Jun 1983 | 1400-1900 LT | 1500 | Seven explosions |
| 09 Jun 1983 | 1500-1800 LT | 1500 | Four explosions |
| 10 Jun 1983 | 0900-2000 LT | 500 | Seven explosions |
| 05-06 Jul 1983 | 2100-0300 LT | -- | Incandescent column |
| 27 Jul 1983 | 1200-1730 LT | 500 | Two explosions |
| 30 Sep 1983 | 0500-0900 LT | 1500 | 7-9 explosions/hour |
| 01 Oct 1983 | 0500-0900 LT | 1000 | 17 explosions |
| 17 Oct 1983 | 0600-1800 LT | Unknown | 15 explosions |
| 18 Oct 1983 | 0530-1130 LT | 1000 | Five explosions |
| 27 Oct 1983 | 1400-2300 LT | 500 | Rumbling |
| 28 Oct 1983 | 0500-1330 LT | 1000 | Rumbling |
| 29 Oct 1983 | 0500- ? LT | 1000 | Rumbling |
| 22 Nov 1983 | 1000-2200 LT | 500 | 10-15 explosions/minute |
| 23 Nov 1983 | 0920-1100 LT | 500 | 15-20 explosions/minute |
| 23 Nov 1983 | 1400-1700 LT | -- | 15-20 explosions/minute |
| 25 Nov 1983 | 0600-1800 LT | 300 | 16 explosions |
| 03 Dec 1983 | 1500-2300 LT | 500 | 2-10 explosions/minute |
| 04 Dec 1983 | 1000-2200 LT | 300 | Six explosions |
| 18 Dec 1983 | 0400-1500 LT | 500 | 2-3 explosions/minute |
| 18 Dec 1983 | 1500-2200 LT | -- | 10 explosions |
| 19 Dec 1983 | 0500-0900 LT | 500 | 15-20 explosions/minute |
| 19 Dec 1983 | 1500-2300 LT | -- | 20 explosions |
| 20 Dec 1983 | 0400-0700 LT | 500 | 2-3 explosions/minute |
| 20 Dec 1983 | 0700-2100 LT | -- | 20 explosions |
| 02 Jan 1984 | 0500-2000 LT | 300 | 13 explosions |
| 26 Jan 1984 | 0600-2200 LT | 300 | 13 explosions |
| 27 Jan 1984 | 500 | 5-7 explosions/hour | |
| 28 Jan 1984 | 0800-2300 LT | 500 | 30-40 explosions/hour |
| 29 Jan 1984 | 0500-1200 LT | 500 | Seven explosions |
| 30 Jan 1984 | 0400-1500 LT | 500 | 10 explosions |
| 14-16 Mar 1984 | -- | -- | 4-5 explosions/minute |
| 18 Mar 1984 | 0500-2300 LT | -- | 10 explosions |
| 12 Apr 1984 | 2100-2300 LT | 1000 | Seven explosions |
| 15 Apr 1984 | 0730-1300 LT | -- | Seven explosions |
| 15 Apr 1984 | 1700-2200 LT | -- | 5-6 explosions |
| 16 Apr 1984 | 0700-1700 LT | -- | Six explosions |
| 17 Apr 1984 | 0500-1000 LT | -- | 12 explosions |
| 18 Apr 1984 | 0600-1000 LT | -- | Three explosions |
| 15 May 1984 | -- | -- | 12-13 explosions |
| 28 Jun 1985 | -- | 2000 | Airplane pilot saw the ash cloud, light ashfall |
| 03 Aug 1985 | -- | -- | Airplane pilot saw the ash cloud |
| 14-15 Sep 1985 | -- | -- | Frequent explosion sounds |
| 01 Oct 1985 | -- | -- | Airplane pilot saw the ash cloud |
| 17-21 Nov 1985 | -- | -- | Frequent explosion sounds |
| 05-06 Dec 1985 | -- | -- | Frequent explosion sounds |
Geological Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island.
Information Contacts: JMA, Tokyo.
