(29o52'38"N, 128o13'28"E)

According to the Volcano Observation Report No. 14 on Suwanosejima volcano issued by JMA at the noon, 13 September 2002, the eruption activity at the summit (Otake) is high in level. Though the activity of the volcano had been relatively quiet since 26 August, it became into a high level in the 12 September morning such that explosive eruptions frequently occurred. According to the Suwanosejima office of Toshima village, rumbling had been heard intermittently at the place about 4 km SSW of the summit and small ash falling was observed on 12 September. Explosions occurred at 0816, 1246, 1746 and 1754 on 12 September, and 0853, 1016 and 1027 on 13 September.

Information contact: JMA-Fukuoka center, N. Uchida;

JMA issued Volcano Observation Report nos. 9 and 10 on Suwanose-jima on August 20 and 21 respectively: eruptive activity still continued, though declined. Volcanic tremor events occurred at 1810-1815 and 1920-1930, on August 19, 0115-0120, August 20, and 0625-0655, August 20. According to the Suwanose-jima office of the Toshima Village, rumbling became smaller, being sometimes accompanied by large explosion sounds on August 20. Faint ash falling was observed in the resident area about 4 km SSW of the summit on August 20 and 21. Ash falling was recorded in the Naze city, Amami-oshima island, about 140 km S of Suwanose-jima on the August 20 afternoon.

Staffs of the Kagoshima Meteorological Observatory inspected the activity from the air, being supported by the Maritime Self-Defense Force. It is likely that he crater of the December 2000 eruption was smoking. The cloud abundant ash was drifting to S in the height of 1,500 m above the crater.

Information contact: JMA-Fukuoka center, N. Uchida;

Eruption clouds on Suwanosejima through live camera images provided by Satellite Image Network Group (SiNG), Faculty of Education, Kagoshima University,
seen from Nakanoshima (about 25 km NE of Suwanosejima)

at 1600, Aug. 21, 2002

JMA issued Volcano Advisory No. 1 on Suwanosejima volcano on the Aug. 19 morning. Volcanic tremor events associated with continuous acoustic signals took place during 20-30 minutes around 00 h and 06h 30m (JST) respectively. The acoustic signals were largest for this one year. According to the Toshima village, they could have heard the explosion sounds every 2 to 3 seconds and continuous rumbling. The summit was covered with cloud. Abundant ash was drifted to SW. The Volcano Observation Report no. 8, successively issued in the afternoon, said that volcanic tremors with continuous large acoustic signals occurred also during 0940-0950, 1410-1500. In addition, small tremor events had occurred. The summit crater was smoking, but the height was not known. Volcanic ash was being drifted to SE.

Information contact: JMA-Fukuoka center, N. Uchida;

Eruption clouds on Suwanosejima through live camera images provided by Satellite Image Network Group (SiNG), Faculty of Education, Kagoshima University,
seen from Nakanoshima (about 25 km NE of Suwanosejima)

at 1640, Aug. 10, 2002 and at 1320, Aug. 16, 2002


JMA issued the Volcano Observation Reports Nos. 8-10 on Suwanosejima during October 11-15. Eruption at Otake crater began around 2 p.m. of Oct. 11, following the latest eruptive activity that ended on July 30. Volcanic tremor event of the eruption that started around noon of October 11 had continued as of the afternoon of October 15. Explosions counted up to eleven times. Acoustic microphone installed in the island recorded four times of shock waves associated with large explosions.

Information contact: N. Uchida of JMA, Fukuoka:


Active eruptions had continued at Otake of Suwanosejima. JMA issued the Observation Reports #6 and 7 on Suwanosejima Volcano on 26 July. According to them, the height of the volcanic plume drifting southward was 1300 m above the crater at 14:30. The JMA seismometer installed about 2 km SW of the crater, recorded explosion at05:01, 05:58, 09:35 and 10:55. Volcanic tremor had continued since around 22 h of 25 July. According to the Suwanosejima Branch of the Toshima Village Office, ash was falling in the 26 July morning.

Information: JMA_Fukuoka, Naokuni Uchida:

(May 14, 2001)

According to the Suwanose-jima Branch of Toshima-Village, whose main office is in a different island, reported that falling of abundant ash was observed around 08:45 on 11 May in the village about 4 km NNW of the active crater (Otake), such that cars could not run without dusting the front windows. The eruptions that occurred during the 12 May evening to the 13 May morning were vigorous, and ash deposition was as thick as 3 cm in the village. At 06:30 on 13 May, still erupting but neither sound nor vibration. It seemed not to be erupted at 09:00 on 14 May, and cleaning of ash deposits from the roads started in the village.

Photos of eruption at Suwanose-jima Volcano on 12 May. Taken from a helicopter of Kagoshima Prefecture by JMA

Infromation contact: JMA;, and VRC:

(May 11, 2001)

According to Sakurajima Volcano Research Center (Sakurajima Volcano Observatory) of Disaster Prevention Research Institute, Kyoto University, eruption plumes had been observed in Suwanosejima volcano, being associated with volcanic tremor events, since the eruption of last December that formed new craters. A tremor event started on the May 9 morning, and the number of events increased since 11 a.m. The events moved into more violent activity associated with acoustic signals around 9 p.m. Such the activity is first since June 1999. Compared with a highly active period before 1995, the amplitude of acoustic signals and the number of occurrence are small. SVRC was calling people's attention to the volcanic activity that may become more explosive.

JMA issued the Volcano Observation Reports #3 and #4 on this volcano on 10 and 11 May, respectively. They include the reports from the Toshima Village officials; the height of gray-colored eruption column was rising about 1,000 to 1,500 m above the crater around the 11 May noon, and ash falling was observed. No felt earthquake reported.

Figure of Daily numbers of eruptions, tremor events, B and A earthquakes (in Japanese) (to the bottom): jump to SVRC site. Here, an eruption is defined as a volcanic earthquake, associated with an acoustic signal more than 1 Pa.
Figure of seismic waves: jump to SVRC site. From the top, up-and-down, south-north, and east-west components. The bottom is an acoustic wave by a microphone.

(Jan. 8, 2001)
The following news comes from the homepage of DPRI, Kyoto University.

A Suwanose-jima's inhabitant reported that a smoke was rising from NE of the summit crater around 5 p.m. (JST) of 19 December 2000. The next day, Prof. Kazuhiro Ishihara of Sakurajima Volcano Research Center (former Sakurajima Volcano Observatory), Kyoto University inspected the crater area from a helicopter of the Kagoshima Prefecture. He observed ash-laden smoke and high-temperature gas emission from new craters formed on the E to NE outer-slope of the summit crater. Observation by Sakurajima Volcano Research Center shows the numbers of volcano quakes deeper than 1 km below the summit had increased a little since the 1999 fall (3 to 10 times a month). Those of volcanic quakes and tremor that are shallower than 1 km had also increased since the early 2000 (20-50 times and 50-300 times a month). Sakurajima Volcano Research Center suggested a relatively high activity but not so high activity as the latest active period in 1992-1993.GPS indicates 1-cm elongation of distance between Suwanose-jima and Nakano-shima, a neighbor island.

Diagram of seismic activity by Sakurajima Volcano Research Center (former Sakurajima Volcano Observatory): in Japanese, monthly numbers of explosion, tremor, and A- and B-type earthquakes from the top.

Prof. Masato Iguchi and Dr. Daisuke Miki of Sakurajima Volcano Research Center inspected the crater area from a helicopter in the morning of 24 December 2000, and measured temperatures of there. i) Two new craters (craters 1 and 2) locates NE of the summit crater (crater 1); 30-50 m away from the rim of crater 1 (crater 2) and 200 m away (crater 3) (map of the crater area). ii) The dimensions of the craters 2 and 3 are 20-30 m and 10 m across, respectively (whole view). iii) Temperature of crater 1 (with white smokes) is about 450 oC, crater 2 (with ash-laden plume) about 100 oC, and crater 3 (with small amount of ash and volcanic gas) about 270 oC. These data indicate the activity had become high, but there is no possibility of a large-scale eruption approaching. Researchers should keep monitoring this activity in these craters.

Geological information of Suwanose-jima by Taketo Shimano

(June 16, 1997)
Ash-falling was observed before noon of 24 March and in the evening of the following day (JMA and Kagoshima Prefectural Government). The heights of ash column were reported to be about 500 and 600 m above the summit. Ash emission was also observed on 16-17 April, the column reached 500-700 m above. SVO, Kyoto University, reported that the B-type earthquakes were abundant in March (ca. 50/mo.), while volcanic tremors were abundant April (ca. 200/mo.).

Information contact: Sakurajima Volcanological Observatory (SVO), Kyoto University, e-mail:; Japan Meteorological Agency (JMA)

(February 10, 1997)
According to JMA and Kagoshima Prefectural Government, explosions at Suwanose-jima Volcano occurred on 26-28 December 1996. The height of eruption column reached up to 600 m above. Small amount of ashfall was observed in a village S of the crater. SVO reported tremors and earthquakes (A- and B-types) in small numbers these months in comparison with the preceding several months.

Information contact: Sakurajima Volcanological Observatory (SVO), Kyoto University; Japan Meteorological Agency (JMA)

(October 2, 1996)
According to JMA and the Kagoshima Prefectural Government, ash falls were confirmed within the island on 1-2 June, 4 June, and 13-14 July. The eruption column on June 2 reached 2100 m high. The explosion earthquakes associated with eruptions in the early June were recorded by the seismological net of SVO (Sakurajima Volcanological Observatory, Kyoto University).

(June 1, 1996)
The activity at Suwanose-jima Volcano has continues in the same levels since 1994, with nearly constant occurrence of A-type earthquakes, according to SVO (Sakurajima Volcanological Observatory, Kyoto University). JMA and Kagoshima Prefectural Government reported ash emissions on 23 February and 5-6 March, and one explosion at 10:58 JST of 14 April. The eruption column in March reached 500 m above the volcano.

(February 1996)
The activity of Suwanose-jima Volcano has been in a high level since 1950, such that one or two events of ash emition occurred every month, sometimes Strombolian explosions. Sakurajima Volcanological Observatory (SVO), which is monitoring the acitivity of volcanoes in SW Islands, reported 9 explosions at this volcano in 1995. According to JMA and Kagoshima Prefectural Government, small eruptions took place during 10-13 January 1996, and the eruption columns reached 300-600 m above the volcano; ash fall in the south.

(left photo) Eruption at Mitake, Suwanose-jima, on Oct. 23, 1989 (taken by T. Kagiyama).

This volcano island, 8 x 5 km with the peak of about 800 m altitude, consists of basaltic andesite and andesite. The largest historical eruption occurred in 1813-14; as a result, thick scoria beds covered the residential area and lava flow descended to the west to southwest from new 300 m-diameter crater. After this event no resident in this island for about 70 years, and, now, around 50 people are living there. Large eruptions also occurred in 1884-85 and lava flow reached the eastern coast.

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