Report on Suwanosejima (Japan) — November 2007

Bulletin of the Global Volcanism Network, vol. 32, no. 11 (November 2007)
Managing Editor: Richard Wunderman.

Suwanosejima (Japan) Eruptions of July 2005-December 2007 send plumes to varying heights

Please cite this report as:

Global Volcanism Program, 2007. Report on Suwanosejima (Japan). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 32:11. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN200711-282030.

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Suwanosejima

Japan

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

All times are local (unless otherwise noted)


Suwanose-jima, in the East China sea, is one of Japan's most active volcanoes. Our last report on Suwanose-jima (BGVN 30:07) tabulated the seismicity and the numerous ash plumes seen between April 2004 and July 2005. The current report continues the tabulation from August 2005 to December 2007 (table 4).

Table 4. Summary of activity reported at Suwanose-jima from August 2005 to December 2007, based on information from the Tokyo VAAC. "?" indicates that data were not reported.

[Skip text table]
    Date                  Event              Plume altitude (km)    Plume direction

    11 Aug-12 Aug 2005    small eruptions         ~ 3.4             --
    22 Sep 2005           plume                   ~ 1.8             W
    07 Oct-09 Oct 2005    eruptions              max. 1.8           SW, E, SE
    01 Jan 2006           explosions                --              --
    10 Jan 2006           explosions              ~ 1.8             E
    24 Jan 2006           plume                     1.5             E
    28 Jan 2006           plume                  max. 1.8           W
    29 Jan 2006           explosion                 --              --
    31 Jan 2006           plume                     1.5             W
    01 Feb 2006           explosions                --              --
    06 Feb-07 Feb 2006    explosions                1.2             NW
    08 Feb-10 Feb 2006    plumes                 max. 1.5           E and SE
    15 Feb-18 Feb 2006    plumes                 max. 1.5           E and S
    22 Feb-24 Feb 2006    eruptions              max. ~ 3           S, E, NE
    02 Mar-08 Mar 2006    explosions             max. ~ 1.8         E, SE, S, NW
    16 Apr 2006           ash plume               ~ 1.5             --
    07 Jun 2006           ash plume                 2.4             --
    30 Jun 2006           plume                     1.2             NE
    16 Jul 2006           ash plume                 1.8             N
    26 Jul-30 Jul 2006    explosions             max. ~ 1.8         N, straight up
    11 Aug-14 Aug 2006    explosions             max. ~ 1.8         N and W
    26 Aug 2006           plumes                    1.8             Straight up
    28 Aug 2006           plumes                    1.5             E
    19 Sep 2006           ash plumes                3.4             E
    20 Sep 2006           ash and steam             2.1             N
    06 Oct 2006           explosion                 --              --
    14, 16-17 Oct 2006    ash plumes                3               --
    18 Oct 2006           explosion                 --              --
    27 Oct-28 Oct 2006    ash plumes                1.8             E
    04 Nov-06 Nov 2006    plumes                    1.2             E and SW
    09 Nov 2006           plume                     1.5             W
    17 Nov 2006           plume                     2.1             Straight up
    19 Dec 2006           eruption                  --              --
    09 Jan 2007           plume                     --              --
    28 Jan 2007           plume                     --              --
    05 Feb-07 Feb 2007    plume                     --              --
    19 Feb-20 Feb 2007    plumes                    --              --
    02 Mar 2007           plume                     1.2             W
    17 Mar 2007           explosion                 --              --
    30 Mar 2007           explosion                 --              --
    02 Apr 2007           explosion                 --              --
    08 May 2007           explosions                --              --
    26 Jul 2007           ash plume                 1.5             SW
    17 Sep 2007           explosions                --              --
    16 Oct 2007           plume                     1.5             E
    22 Oct 2007           plume                     1.5             W
    26 Oct-28 Oct 2007    plumes                    1.5             E and W
    29 Nov-02 Dec 2007    plumes                 1.2 - 1.8          E
    10 Dec 2007           plumes                 1.5 - 1.8          W
    14 Dec-17 Dec 2007    plumes                 1.5 - 1.8          E

During the reporting interval, the Tokyo Volcanic Ash Advisory Center reported small explosions or eruptions, usually accompanied by ash plumes, every month during this period, except for November and December 2005, May 2006, and June 2007. Ash was seldom identified on satellite imagery. On 20 September 2006, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite detected ash-and-steam emissions (figure 11).

Figure (see Caption) Figure 11. Ash plume blowing N from Suwanose-jima on 20 September 2006, seen in a MODIS image. In color images the plume's hue clearly distinguishes it from the banks of transversely oriented white weather clouds. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response team.

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 (Tokyo VAAC), Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (URL: http://www.jma.go.jp/JMA_HP/jma/jma-eng/jma-center/vaac/, Email: vaac@eqvol.kishou.go.jp); NASA Moderate Resolution Imaging Spectroradiometer (MODIS) program (URL: http://modis.gsfc.nasa.gov/).