Report on Suwanosejima (Japan) — July 2005

Bulletin of the Global Volcanism Network, vol. 30, no. 7 (July 2005)
Managing Editor: Edward Venzke.

Suwanosejima (Japan) Eruptions during April 2004-July 2005 send plumes to varying heights

Please cite this report as:

Global Volcanism Program, 2005. Report on Suwanosejima (Japan). In: Venzke, E (ed.), Bulletin of the Global Volcanism Network, 30:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200507-282030.

Volcano Profile |  Complete Bulletin


Suwanosejima

Japan

29.638°N, 129.714°E; summit elev. 796 m

All times are local (unless otherwise noted)


Several small eruptions during December 2003 and January 2004 at Suwanose-jima produced ash plumes to unknown heights (BGVN 29:03). Little activity was observed during the first four months of 2004. From the end of April 2004 to the end of July 2005, numerous eruptions and explosions produced plumes reported by the Tokyo Volcanic Ash Advisory Center (VAAC), including some observed by pilots (table 3).

Table 3. Summary of activity at Suwanose-jima from April 2004 to July 2005 based on information from the Tokyo VAAC. "--" indicates data not reported or unknown.

Date Time Period Plume Altitude (km) Drift Direction Activity
28 Apr 2004 -- 3 SE Ash emission
01 May 2004 0906 -- -- Explosion
07 Jun 2004 -- 2 E Gas plume
08 Jun 2004 -- 2 E Gas and ash
09 Jun 2004 1003 1.8 E Ash plume
09 Jun 2004 1300 -- -- Ash plume
30 Jun-05 Jul 2004 various max 1.9 -- Several explosions
30 Nov 2004 1607 1.2 -- Eruption
20 Dec 2004 -- 1.8 SE Eruption
21 Dec 2004 -- -- SE Eruption
22 Dec 2004 -- -- -- Ash plume
24 Dec 2004 -- -- -- Ash plume
25 Dec 2004 -- -- -- Ash plume
27 Dec 2004 -- -- -- Ash plume
29 Dec 2004 -- 1.2 -- Ash plume
01 Jan 2005 -- -- -- Eruption
04 Jan 2005 -- -- -- Eruption
06 Mar 2005 -- 1.5 -- Ash emission
08 Mar 2005 -- 1.2 -- Ash emission
09 Mar 2005 -- 1.8 -- Ash plume
26 Apr 2005 -- 1.2 E Eruption
26 May-31 May 2005 various max 2.1 -- Several ash explosions
01 Jun-06 Jun 2005 various Several ash explosions 1.8 --
06 Jul 2005 various -- -- Several ash explosions
27 Jul 2005 -- 0.8 -- Eruption with ash
28 Jul 2005 -- 2.4 -- Ash plume

Geologic Background. The 8-km-long, spindle-shaped island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanosejima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from Otake, the NE summit crater, that began in 1949 and lasted until 1996, after which periods of inactivity lengthened. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed 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 the horseshoe-shaped Sakuchi caldera, which extends 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: Tokyo Volcanic Ash Advisory Center, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (URL: https://ds.data.jma.go.jp/svd/vaac/data/).