Suwanosejima

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  • 29.638°N
  • 129.714°E

  • 796 m
    2611 ft

  • 282030
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Most Recent Weekly Report: 3 September-9 September 2014


Tokyo VAAC released ash advisories for Suwanosejima during 3-4 and 9 September based on JMA reports. Ash drifted NE and N at 1,800-5,500 m (6,000-18,000 ft) a.s.l. on 3 September. On 4 September, an ash plume at 5,500 m (18,000 ft) a.s.l. was observed. JMA also reported a 2,100 m (7,000 ft) a.s.l. ash plume on 9 September at 2233.

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)


Most Recent Bulletin Report: April 2013 (BGVN 38:04)


Near continuous tremor between July 2012 and March 2013

This report discusses Suwanose-jima (figure 16) during July 2012 through April 2013, an interval with generally abundant tremor, low numbers of earthquakes, weak plumes (less than 0.7 km above the crater rim), and occasional intermittent eruptions. Our previous report on Suwanose-jima discussed seismicity through June 2012 that included volcanic earthquakes and tremor, minor explosions, and plumes which occasionally deposited ash on nearby Toshima village as late as June 2012 (BGVN 37:08).

Figure 16. Satellite image showing the location of Suwanose-jima. Courtesy of Google Earth.

Recent monthly reports of volcanic activity from the Japan Meteorological Agency (JMA) translated into English resumed in October 2010. Since June 2012, English-translated JMA reports on Suwanose-jima were available online every month through March 2013

According to JMA, seismic activity at Suwanose-jima remained at low levels between July 2012 and March 2013. Although explosive eruptions have occurred repeatedly in the past, no such eruption occurred during the reporting period. However, JMA reported infrequent tiny eruptions. Volcanic tremor occurred almost continually between 28 September 2012 and March 2013. A high-sensitivity camera often detected a weak night glow during every month. No unusual ground deformation was seen in GPS observation data. Table 11 summarizes tremor activity and other information reported by JMA.

Table 11. A compilation of data on Suwanose-jima between July 2012 and March 2013. '-' indicates data not reported. A-type earthquakes are generally considered to have shallow focal depths; B-type earthquakes, deeper focal depths. An asterisk "*" in the earthquake column indicates that the number of events reported for a specific month conflicts with the number reported for that same month in the sequential monthly JMA report. Data courtesy of JMA.

    Month       Earthquakes          Tremor duration    Max plume height                                     (hours:minutes)    (m above crater rim)                Other activity    Jul 2012    29 A-type events,    38:5               400                                     123 B-type events        Eruption.    Aug 2012    17 A-type events,    0:0 (or 0:1)*      300                39 B-type events                               (or 60 events)*             No eruption.  Plume on 19 Aug only.    Sep 2012    37 A-type events,    0:1 (or 67:52)*    300-400                86 B-type events                   (or 74 events)*           No eruption.  White plumes.  11 Sep aerial observation spotted white        plume above Shindake crater.    Oct 2012    22 A-type events,    705:19             700                      78 B-type events.        Tiny intermittent eruptions at Otake crater.  According to Tokyo VAAC,        an ash plume on 3 Oct drifted SW at altitude of 3 km (i.e. 1.5 km        higher than the JMA reported).  Ashfall on Toshima village, 4 km SSW        of Otake, on 2 and 5 Oct.    Nov 2012    --                   720:0              500-600                 Tiny intermittent eruptions.  Tiny amount of ashfall on Toshima village           on 25 Nov.    Dec 2012    --                   622:23             500               Tiny intermittent eruptions on 26th, red hot mass seen.     Jan 2013    --                   744:0              500            White plumes    Feb 2013    --                   672:0              500               M 3.6 earthquake on 19 Feb with aftershocks.  Tiny intermittent eruption        on 3 Feb.  Tiny amount of ashfall on Toshima village on 3 Feb.     Mar 2013    --                   --                  500            Tremor data unavailable.    Apr 2013    --                   --                  700                                                                                Small eruption on 13 April. Tremor data unavailable.

 

On 8 November 2012, a field survey at Bunka crater revealed no remarkable change in the crater's shape. Infrared images showed no significant change in the crater's temperature distribution. On 26 December 2012, an aerial observation revealed a red-hot lava mass inside Otake crater. This phenomenon has occasionally been observed in past observations.

On 19 February 2013, a M 3.6 earthquake occurred (apparently at Suwanose-jima). The earthquake's maximum seismic intensity on JMA's scale was 3 (felt indoors by most or all people, objects rattle and fall off tables, houses shake strongly and may receive slight damage). In addition, a swarm of ten earthquakes (aftershocks?) with seismic intensities of 1 or greater on JMA's scale were recorded. These earthquakes caused no significant changes in surface phenomena or tiltmeter data. Seismicity remained at low levels, with hypocenters located just beneath the Otake crater.

Information Contacts: Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html ); Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/ ).

Index of Weekly Reports


2014: January | February | April | June | August | September
2013: July | August | September | October | November | December
2012: January | February | October
2011: January | February | March | April | July | September | October
2010: January | February | March | April | May | July | August | September | October | November | December
2009: January | February | March | April | May | June | July | August | September | October | November | December
2008: February | March | April | June | July | August | September | October | November | December
2007: January | February | March | May | July | September | October | November | December
2006: January | February | March | April | June | July | August | September | October | November | December
2005: March | April | May | June | July | August | September
2004: January | April | June | November | December
2003: December
2002: June | August | September
2001: January | May | July | October

Weekly Reports


3 September-9 September 2014

Tokyo VAAC released ash advisories for Suwanosejima during 3-4 and 9 September based on JMA reports. Ash drifted NE and N at 1,800-5,500 m (6,000-18,000 ft) a.s.l. on 3 September. On 4 September, an ash plume at 5,500 m (18,000 ft) a.s.l. was observed. JMA also reported a 2,100 m (7,000 ft) a.s.l. ash plume on 9 September at 2233.

Sources: Japan Meteorological Agency (JMA); Tokyo Volcanic Ash Advisory Center (VAAC)


27 August-2 September 2014

During 28 August-1 September, the Tokyo VAAC reported eruptions at Suwanosejima. Ash plumes rose 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted E, SE, S, and NE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


18 June-24 June 2014

During 18-20 June, JMA reported explosions at Suwanosejima. Ash plumes were not visible in satellite images. Explosions occurred at 1346 on 18 June, 0834 on 19 June with a plume drifting E, and at 0033 on 20 June.

Sources: Japan Meteorological Agency (JMA); Tokyo Volcanic Ash Advisory Center (VAAC)


23 April-29 April 2014

The Tokyo VAAC reported that on 29 April an explosion at Suwanosejima produced a plume that rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


19 February-25 February 2014

The Tokyo VAAC reported an explosion from Suwanosejima on 19 February. Explosions during 23-24 February produced plumes that rose to an altitude of 1.8 km (6,000 ft) a.s.l. An ash plume on 24 February drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 February-18 February 2014

The Tokyo VAAC reported explosions from Suwanosejima during 12-14 February. On 12 February a plume rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted SE, and on 14 February a plume rose to an altitude of 1.8 km (6,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 January-4 February 2014

Based on JMA notices and pilot observations, the Tokyo VAAC reported that on 2 February ash plumes from Suwanosejima rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and drifted SE and SSE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 January-28 January 2014

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanosejima on 24 January generated a plume that rose to an altitude 1.8 km (6,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


8 January-14 January 2014

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanosejima during 8-9 January sometimes generated plumes that rose to an altitude 1.2 km (4,000 ft) a.s.l. and drifted NE and SE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 January-7 January 2014

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 1-3 and 6 January. Explosions during 1-2 January generated plumes that rose to altitudes 0.9-1.8 km (3,000-6,000 ft) a.s.l. and drifted SE. JMA noted that the Alert Level remained at 2 (on a scale of 1-5).

Sources: Japan Meteorological Agency (JMA); Tokyo Volcanic Ash Advisory Center (VAAC)


25 December-31 December 2013

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 26-30 December. Explosions during 27-28 December generated plumes that rose to an altitude over 1.5 km (5,000 ft) a.s.l. and drifted SE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


27 November-3 December 2013

Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima on 27 November generated a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


16 October-22 October 2013

According to the Tokyo VAAC, a pilot observed an ash plume from Suwanose-jima on 21 October. Based on information from JMA the VAAC noted that a plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted S that same day.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 September-17 September 2013

According to the Tokyo VAAC, the JMA reported that on 12 September an eruption from Suwanose-jima generated an ash plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted NW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


4 September-10 September 2013

According to the Tokyo VAAC, the JMA reported that during 5-6 September explosions from Suwanose-jima generated ash plumes that rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW and N.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 August-3 September 2013

According to the Tokyo VAAC, the JMA reported that on 28 August pilots observed ash plumes from Suwanose-jima that rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted E and NW. Explosions during 28-29 August generated ash plumes that rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE. Ash was detected in satellite images on 29 August, and explosions were detected on 30 August and 1 September.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


21 August-27 August 2013

According to the Tokyo VAAC, the JMA reported explosions from Suwanose-jima during 26-27 August. Plumes rose to an altitude of 1.2 km (4,000 ft) a.s.l. on 27 August, and drifted NE and SE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


3 July-9 July 2013

According to the Tokyo VAAC, a pilot observed an ash plume from Suwanose-jima that rose to an altitude of 1.5 km (5,000 ft) a.s.l. Ash was not detected in satellite images.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


3 October-9 October 2012

Based on a pilot observation, the Tokyo VAAC reported that on 3 October an ash plume from Suwanose-jima drifted SW at altitude of 3 km (10,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 February-6 March 2012

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 6 March. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 February-7 February 2012

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 6 February. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 January-17 January 2012

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 12 January. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


19 October-25 October 2011

Based on a pilot observation, the Tokyo VAAC reported that on 14 October an ash plume from Suwanose-jima rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted SE. Ash was not detected in satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


7 September-13 September 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 12 September. That same day an eruption produced a plume that rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


13 July-19 July 2011

Based on a pilot observation, the Tokyo VAAC reported that on 14 July an ash plume from Suwanose-jima rose to an altitude of 3.7 km (12,000 ft) a.s.l. Ash was not detected in satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


27 April-3 May 2011

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 3 May. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 April-12 April 2011

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima on 12 April produced a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


16 March-22 March 2011

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 19-20 March. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 March-15 March 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 15 March. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 March-8 March 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 3 March. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 February-15 February 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 9 and 14 February. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 February-8 February 2011

Based on a pilot observation, the Tokyo VAAC reported that on 5 February an ash plume from Suwanose-jima rose to an altitude of 0.7 km (2,000 ft) a.s.l. and drifted S. Explosions during 5-7 February were noted by JMA.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


19 January-25 January 2011

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 22-23 and 25 January. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted S on 23 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 January-18 January 2011

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 12-13 and 15 January. A plume rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted SE on 13 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


5 January-11 January 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima during 11-12 January. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 December-4 January 2011

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 29 December. Details of a possible resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 December-21 December 2010

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 20 December. Details of possible a resulting plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 December-7 December 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 1-4 December. Plumes rose to an altitude of 1.2 km (4,000 ft) and drifted SE on 4 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 November-30 November 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 27 November-1 December. Plumes rose to a maximum altitude of 1.5 km (5,000 ft) on 29 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 November-23 November 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 18-23 November. Plumes rose to an altitude of 1.8 km (6,000 ft) on 18 November and to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE on 21 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 November-16 November 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 10 and 12 November. On 11 November a pilot reported an ash plume. A subsequent satellite image showed that the ash had dissipated. The next day, a pilot reported that an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted S.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 October-26 October 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 26 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


13 October-19 October 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 16-17 October. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SE on 17 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 September-5 October 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 3-5 October. A plume drifted E on 5 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 September-28 September 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 22, 25, and 27-28 September. A pilot observed an ash plume on 22 September that rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE. JMA noted that plumes on 25 September rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 September-21 September 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 19-21 September. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


8 September-14 September 2010

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 11 September. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 August-31 August 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 25 and 27 August. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


18 August-24 August 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 21-24 August. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


21 July-27 July 2010

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima produced plumes that rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 23 July and to an altitude of 2.4 km (8,000 ft) a.s.l. on 26 July. Plumes drifted NW and W, respectively.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


14 July-20 July 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 17 and 19 July. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 May-18 May 2010

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during 15-16 May produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted N and NW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 April-4 May 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 29 April, and during 1 and 4-5 May. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


31 March-6 April 2010

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 2 April. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 March-30 March 2010

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 29 March. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 February-23 February 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 17-19 and 21-22 February. Plumes occasionally rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted E and SE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 February-16 February 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 11-16 February. Details of possible resulting plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


3 February-9 February 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 5-6 and 9 February. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


27 January-2 February 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 27 January-2 February. On 27 January, plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted W. Plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 29 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 January-26 January 2010

During 29-30 December 2009, a visitor to Suwanose-jima observed and photographed multiple Strombolian explosions and ash eruptions from On-take (Otake) crater. Based on information from JMA, the Tokyo VAAC reported explosions during 22-26 January. On 24 and 26 January, plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l.

Sources: Tokyo Volcanic Ash Advisory Center (VAAC); Richard Roscoe, Photo Volcanica


13 January-19 January 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 13 and 16-17 January. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 January-12 January 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 6-9 and 11 January. Plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 6 and 9 January and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


30 December-5 January 2010

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 30 December-2 January and 4-5 January. Plumes rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. on 2 and 4 January, and drifted NE and E on 4 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


23 December-29 December 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 24, 26, and 28-29 December. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


16 December-22 December 2009

Based on information from JMA, the Tokyo VAAC reported eruptions from Suwanose-jima during 17-20 and 22 December. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 22 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 December-15 December 2009

Based on information from JMA, the Tokyo VAAC reported eruptions from Suwanose-jima on 14 and 15 December. Plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 December-8 December 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima during 5-6 December. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 November-1 December 2009

The Tokyo VAAC reported that on 26 November an ash plume from Suwanose-jima was seen by a pilot 65 km S drifting NE at an altitude of 3 km (10,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


18 November-24 November 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 18 November. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 November-17 November 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 12 and 16 November. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


4 November-10 November 2009

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during 4-5 November produced plumes that rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted SW and W. An explosion was also reported on 6 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 October-3 November 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 30 October and 2 November. Details of possible resulting emissions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


7 October-13 October 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 10 and 11 October. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 10 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


30 September-6 October 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 1 October. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and rifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


16 September-22 September 2009

Based on information from JMA and pilot observations, the Tokyo VAAC reported that on 17 September ash from Suwanose-jima drifted S. On 19 September, an ash plume rose to an altitude of 1.5 km (5,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 September-15 September 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 13-14 September. Details of possible resulting ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 September-8 September 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 3-7 September. Details of possible resulting ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


26 August-1 September 2009

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during 27-29 August sometimes produced plumes that rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 August-18 August 2009

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during 16-17 August produced plumes that rose to an altitude of 1.8 km (6,000 ft) a.s.l. Plumes drifted E on 16 August.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


5 August-11 August 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 10 August. Details of a possible resultant ash plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 July-4 August 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 5 August. Details of possible resultant ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 July-28 July 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 23-24 July. Details of possible resultant ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 July-21 July 2009

Based on a pilot observation, the Tokyo VAAC reported that on 15 July an ash plume from Suwanose-jima rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE. Eruptions reported by the JMA during 16-17 July produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted NE and W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 July-7 July 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 6 July. Details of a possible resultant ash plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 June-16 June 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 16 June. Details of a possible resultant ash plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 May-26 May 2009

Based on analysis of satellite imagery and pilot observations, the Tokyo VAAC reported that on 25 May an ash plume from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


13 May-19 May 2009

The Tokyo VAAC reported an explosion from Suwanose-jima on13 May, as stated by JMA. Details of possible resultant ash plumes were not reported. Based on analysis of satellite imagery and a pilot observation, the VAAC also reported that on 17 May an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 May-12 May 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 7-9 and 12 May. Details of possible resultant ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 April-5 May 2009

Based on information from JMA, the Tokyo VAAC reported that eruptions from Suwanose-jima during 29 April-1 May produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. Plumes drifted W on 30 April and 1 May.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 April-28 April 2009

The Tokyo VAAC reported that a pilot saw an ash plume from Suwanose-jima on 22 April. JMA reported that an eruption the next day produced ash plumes to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted E and S. On 27 April, an explosion was reported but details of a possible resultant ash plume were not. On 28 April, explosions produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 April-21 April 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 21 April. Details of possible resultant ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


8 April-14 April 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 8 and 10 April. Details of possible resultant ash plumes on either day were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 April-7 April 2009

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 6 April.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 March-31 March 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 28 March. JMA reported three explosions on 30 March. Details of possible resultant ash plumes on either day were not reported.

Sources: Japan Meteorological Agency (JMA); Tokyo Volcanic Ash Advisory Center (VAAC)


11 March-17 March 2009

Based on information from JMA, the Tokyo VAAC reported that on 15 and 16 March eruptions from Suwanose-jima produced plumes that rose to an altitude of 1.5 km (5,000 ft) a.s.l. Plumes drifted E on 15 March.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


4 March-10 March 2009

Based on information from JMA, the Tokyo VAAC reported multiple explosions from Suwanose-jima on 6 March. Details of possible resultant ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 February-3 March 2009

Based on information from JMA, the Tokyo VAAC reported multiple explosions from Suwanose-jima during 26 February-1 March. On 1 March, resultant plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted E. On 2 March, an eruption produced a plume to an altitude of 1.5 km (5,000 ft) a.s.l. An explosion was reported on 3 March.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


18 February-24 February 2009

JMA reported that Suwanose-jima erupted explosively on 18 February; a colored plume rose 400 m above the crater and drifted E. Two explosive eruptions occurred the next day. Based on information from JMA, the Tokyo VAAC reported explosions on 20 and 21 February. Details of possible resultant ash plumes were not reported.

Sources: Japan Meteorological Agency (JMA); Tokyo Volcanic Ash Advisory Center (VAAC)


21 January-27 January 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 21 January. Details of a possible resultant ash plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


7 January-13 January 2009

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 9 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


31 December-6 January 2009

Based on information from JMA, the Tokyo VAAC reported an eruption from Suwanose-jima on 3 January. A plume rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 December-30 December 2008

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 26-28 and 30 December. Plumes rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. during 27-28 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 December-23 December 2008

Based on information from JMA, the Tokyo VAAC reported that during 17 and 19-20 December explosions or eruptions from Suwanose-jima produced plumes to an altitude of 1.5 km (5,000 ft) a.s.l. Plumes drifted E on 17 and 19 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 December-16 December 2008

Based on information from JMA, analysis of satellite imagery, and pilot reports, the Tokyo VAAC reported explosions or eruptions from Suwanose-jima during 10-12 and 14-16 December. Plumes rose to altitudes of 0.9-1.8 km (3,000-6,000 ft) a.s.l. and drifted E. Details of a possible ash plume on 14 and 16 December were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


19 November-25 November 2008

Based on information from JMA, the Tokyo VAAC reported an eruption from Suwanose-jima on 21 November. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted E. An explosion was reported on 25 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 November-18 November 2008

Based on analysis of satellite imagery and information from JMA, the Tokyo VAAC reported multiple explosions or eruptions from Suwanose-jima during 12-16 November. Occasional plumes rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. during 13-15 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


5 November-11 November 2008

Based on pilot observations and analysis of satellite imagery, the Tokyo VAAC reported that on 5 November an ash plume from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted NE. The JMA indicated that during 7-8 November explosion or eruption plumes rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted E. An explosion was reported on 12 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 October-4 November 2008

Based on information from JMA, the Tokyo VAAC reported that during 29-30 October and 3 November Suwanose-jima produced explosion or eruption plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E. Explosions were reported on 31 October and 1 November, but details of possible ash plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 October-28 October 2008

Based on information from JMA, the Tokyo VAAC reported that Suwanose-jima produced explosion or eruption plumes that rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted W and E during 21, 23, 25-26, and 28 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 October-21 October 2008

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during 16 and 18-20 October produced plumes that rose to altitudes of 1.2-2.4 km (4,000-8,000 ft) a.s.l. and drifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


8 October-14 October 2008

Based on reports from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 9 and 11 October. The altitude and direction of a possible resultant plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 October-7 October 2008

Based on reports from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 1, 3, 7, and 8 October. Plumes rose straight up to an altitude of 2.1 km (7,000 ft) a.s.l. on 8 October. The altitude and direction of plumes were not reported for the other days.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 September-30 September 2008

Based on reports from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 25-26 and 28-29 September. Resultant plumes rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted NE, E, and SW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


3 September-9 September 2008

Based on reports from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 5-7 September. Resultant plumes rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. Plumes drifted E on 5 September.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 August-26 August 2008

Based on reports from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 24-26 August. Resultant plumes rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. during 25-26 August.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 August-12 August 2008

Based on reports from JMA, the Tokyo VAAC reported that on 7 August an eruption plume from Suwanose-jima rose to an altitude of 1.2 km (4,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


23 July-29 July 2008

Based on pilot reports, the Tokyo VAAC reported that on 30 July an ash plume from Suwanose-jima rose to an altitude of 0.6 km (2,000 ft) a.s.l. and drifted S.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 June-17 June 2008

Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima occurred on 17 June. The altitude and direction of a possible resultant plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


16 April-22 April 2008

Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima occurred on 16 April. The altitude and direction of a possible resultant plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


19 March-25 March 2008

Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima occurred on 22 March. The altitude and direction of a possible resultant plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 February-12 February 2008

Based on information from JMA, the Tokyo VAAC reported that an eruption plume from Suwanose-jima rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 7 February and drifted E. Explosions were also noted on 8, 9, and 13 February, but altitude and direction of possible plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 December-18 December 2007

Based on information from JMA, the Tokyo VAAC reported that eruption plumes from Suwanose-jima rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. during 14-17 December and drifted E. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


5 December-11 December 2007

Based on information from JMA, the Tokyo VAAC reported that eruption plumes from Suwanose-jima rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. on 10 December and drifted W. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 November-4 December 2007

Based on information from JMA, the Tokyo VAAC reported that eruption plumes from Suwanose-jima rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. during 29 November-2 December and drifted E. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 October-30 October 2007

Based on information from JMA, the Tokyo VAAC reported that eruption plumes from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l. during 26-28 October and drifted E and W. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 October-23 October 2007

Based on information from JMA, the Tokyo VAAC reported that an eruption plume from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 22 October and drifted W. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 October-16 October 2007

Based on information from JMA, the Tokyo VAAC reported that an eruption plume from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 16 October and drifted E. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 September-18 September 2007

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 17 September. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 July-31 July 2007

Based on information from JMA and a pilot report, the Tokyo VAAC reported that an ash plume from Suwanose-jima rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SW on 26 July. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 May-8 May 2007

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 8 May. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 March-3 April 2007

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 30 March and 2 April. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


14 March-20 March 2007

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 17 March. Ash was not seen on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 February-6 March 2007

Based on information from JMA, the Tokyo VAAC reported that on 2 March an eruption plume from Suwanose-jima rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


14 February-20 February 2007

Based on information from JMA and satellite imagery, the Tokyo VAAC reported that an explosion from Suwanose-jima produced eruption plumes during 19-20 February. The altitude and direction of the plumes were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


7 February-13 February 2007

Based on information from JMA and satellite imagery, the Tokyo VAAC reported that an explosion from Suwanose-jima produced an eruption plume during 7 February. The altitude and direction of the plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


31 January-6 February 2007

Based on information from JMA and satellite imagery, the Tokyo VAAC reported that an explosion from Suwanose-jima produced an eruption plume during 5-6 February. The altitude and direction of the plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 January-30 January 2007

Based on information from JMA, the Tokyo VAAC reported an eruption plume from Suwanose-jima on 28 January. The altitude and direction of the plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


3 January-9 January 2007

Based on information from JMA, the Tokyo VAAC reported an eruption plume from Suwanose-jima on 9 January. The altitude and direction of the plume were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 December-26 December 2006

Based on information from JMA, the Tokyo VAAC reported that an eruption from Suwanose-jima occurred on 19 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 November-21 November 2006

Based on information from JMA, the Tokyo VAAC reported that on 17 November an eruption plume from Suwanose-jima rose straight up to an altitude of 2.1 km (7,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


8 November-14 November 2006

Based on information from JMA, the Tokyo VAAC reported that on 9 November an eruption plume from Suwanose-jima reached an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 November-7 November 2006

Based on satellite imagery and information from JMA, the Tokyo VAAC reported that during 4-6 November eruption plumes from Suwanose-jima reached altitudes of 1.2 km (4,000 ft) a.s.l. The plumes drifted E and SW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 October-31 October 2006

Based on information from JMA, the Tokyo VAAC reported that on 27 and 28 October, ash plumes from Suwanose-jima reached altitudes of 1.8 km (6,000 ft) a.s.l. Plumes drifted E on 28 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


18 October-24 October 2006

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 18 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 October-17 October 2006

Based on information from JMA and a pilot report, the Tokyo VAAC reported that on 14, 16, and 17 October, ash plumes from Suwanose-jima reached altitudes of 3 km (10,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


4 October-10 October 2006

Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 6 October.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


20 September-26 September 2006

On 20 September the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite caught Suwanose-jima in the process of emitting volcanic ash and steam. The volcano's emissions blew N, gradually fanning out over the ocean, with a grayish tinge that distinguished it from nearby white clouds. Aviation ash advisories for this eruption issued by the Tokyo VAAC based on satellite imagery, pilot reports, and JMA, noted that the plume rose to 2.1 km (7,000 ft) a.s.l. and extended about 80 km N.

Sources: NASA Earth Observatory; Tokyo Volcanic Ash Advisory Center (VAAC)


13 September-19 September 2006

Based on information from JMA and a pilot report, the Tokyo VAAC reported on 19 September that ash plumes from Suwanose-jima reached altitudes of 3.4 km (11,000 ft) a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


23 August-29 August 2006

Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima produced eruption plumes that rose straight up to 1.8 km (6,000 ft) a.s.l. on 26 August. On 28 August, eruption plumes rose to altitudes of 1.5 km (5,000 ft) a.s.l. and drifted E. Ash was not identified on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 August-15 August 2006

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 11-14 August. The resulting plumes reached maximum altitudes of 1.8 km (6,000 ft) a.s.l. and drifted N and W. Ash was not identified on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


26 July-1 August 2006

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 26-30 July. The resulting plumes reached maximum altitudes of 1.8 km (6,000 ft) a.s.l. and drifted N. Ash was not identified on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 July-18 July 2006

A pilot observed an ash plume from Suwanose-jima on 16 July that reached an altitude of 1.8 km (6,000 ft) a.s.l. and drifted N. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 June-4 July 2006

Based on information from JMA, the Tokyo VAAC reported on 30 June that a small plume from Suwanose-jima reached an altitude of 1.2 km (4,000 ft) a.s.l. and drifted NE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


7 June-13 June 2006

A pilot observed ash from Suwanose-jima on 7 June at an altitude of 2.4 km (8,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


12 April-18 April 2006

Based on information from JMA and an aircraft report, the Tokyo VAAC reported that ash from Suwanose-jima was visible at a height of ~1.5 km (5,000 ft) a.s.l. on 16 April.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 March-7 March 2006

Based on information from JMA, the Tokyo VAAC reported that several explosions occurred at Suwanose-jima during 2-7 March. The highest plume reached ~1.8 km (6,000 ft) a.s.l. on 5 March.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 February-28 February 2006

Based on information from JMA, the Tokyo VAAC reported that during 22-24 February several small eruptions occurred at Suwanose-jima. The highest rising plume reached ~3 km (10,000 ft) a.s.l. after an eruption on 23 February.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 February-7 February 2006

Based on information from JMA, the Tokyo VAAC reported that several explosions occurred at Suwanose-jima during 6-7 February. A resultant plume from an explosion on the 6th rose to 1.2 km (4,000 ft) a.s.l. and extended NW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


4 January-10 January 2006

Based on information from JMA, the Tokyo VAAC reported that explosions occurred at Suwanose-jima on 1 and 10 January. An explosion on 10 January produced an ash plume to a height of ~1.8 km (6,000 ft) a.s.l. The heights of ash clouds from other explosions were not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


21 September-27 September 2005

Based on information from JMA, the Tokyo VAAC reported that an emission from Suwanose-jima on 22 September reached a height of ~1.8 km (6,000 ft) a.s.l. and drifted W. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 August-16 August 2005

Based on information from JMA, the Tokyo VAAC reported that small eruptions at Suwanose-jima on 11 and 12 August produced ash plumes to a height of ~3.4 km (11,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


27 July-2 August 2005

A pilot observed ash from Suwanose-jima on 28 July at a height of 2.4 km (~8,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


6 July-12 July 2005

Based on information from JMA, the Tokyo VAAC reported that an explosion occurred at Suwanose-jima on 6 July at 1400. The height of the resultant ash cloud was not reported.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


1 June-7 June 2005

Based on information from JMA, the Tokyo VAAC reported that during 1-6 June several explosions at Suwanose-jima produced ash clouds. The only known height of an ash cloud was ~1.8 km (5,900 ft) a.s.l. from an explosion on 1 June.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


25 May-31 May 2005

Based on information from JMA, the Tokyo VAAC reported that several explosions occurred at Suwanose-jima during 26-31 May. The highest reported plume rose to ~2.1 km (~7,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


27 April-3 May 2005

Based on information from JMA, the Tokyo VAAC reported that an eruption at Suwanose-jima on April 26 produced a plume to 1.2 km (4,000 ft) a.s.l. that extended E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 March-15 March 2005

Based on information from JMA, the Tokyo VAAC reported that an explosion at Suwanose-jima on 9 March produced an ash plume to a height of ~1.8 km a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 March-8 March 2005

Based on information from JMA, the Tokyo VAAC reported that emissions from Suwanose-jima on 6 and 8 March produced ash plumes that rose to 1.5 and 1.2 km a.s.l., respectively.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


29 December-4 January 2005

On 29 December, the Tokyo VAAC reported an eruption at Suwanose-jima that produced an ash plume to ~1.2 km a.s.l. Eruptions were also reported on 1 and 4 January, but no plumes were visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


22 December-28 December 2004

Based on information from JMA, the Tokyo VAAC reported that eruptions at Suwanose-jima produced ash plumes to unknown heights on 22, 24, 25, and 27 December. The plumes were not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


15 December-21 December 2004

Based on information from JMA, the Tokyo VAAC reported that an eruption at Suwanose-jima on 20 December produced a SE-drifting plume to ~1.8 km a.s.l. Also, on 21 December an eruption produced a SE-drifting ash plume to an unknown height.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 November-30 November 2004

Based on information from JMA, the Tokyo VAAC reported that an eruption occurred at Suwanose-jima on 30 November at 1607. The eruption produced a plume to a height of ~1.2 km.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


30 June-6 July 2004

Based on information from JMA, the Tokyo VAAC reported that several explosions occurred at Suwanose-jima during 30 June to 5 July. The highest rising plume reached ~1.9 km a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


9 June-15 June 2004

An eruption at Suwanose-jima on 9 June at 1003 produced an ash plume visible on satellite imagery at a height of ~1.8 km a.s.l., extending E. Another explosion at 1300 that day produced an ash plume that reached an unknown height.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


2 June-8 June 2004

On 7 June Suwanose-jima erupted, producing a plume to ~2 km a.s.l. that extended E. Eruptions continued through 8 June with at least one explosion producing a gas-and-ash plume to ~2 km a.s.l. that also drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


28 April-4 May 2004

According to the Tokyo VAAC, ash emitted from Suwanose-jima was reported on 28 April at a height of ~3 km a.s.l. extending SE. No ash was visible on satellite imagery. JMA reported that an explosion occurred on 1 May at 0906, but it was not known if an ash cloud was produced.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


21 January-27 January 2004

Based on information from the Japanese Meteorological Agency, the Tokyo VAAC reported that explosions at Suwanose-jima on 21 and 22 January produced ash plumes to unknown heights.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


31 December-6 January 2004

Based on information from JMA, the Tokyo VAAC reported that on 2 and 4 January small explosions occurred at Suwanose-jima producing ash plumes to unknown heights.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


24 December-30 December 2003

Based on information from JMA, the Tokyo VAAC reported that several small ash emissions from Suwanose-jima on 27 and 28 December rose to unknown heights. Ash from an eruption on 28 December at 0820 reached a height of ~1.5 km a.s.l. and drifted E.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 December-23 December 2003

Based on information from the Japanese Meteorological Agency, the Tokyo VAAC reported that an explosion at Suwanose-jima on 21 December at 1828 produced a plume to an unknown height.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


10 December-16 December 2003

Based on information from JMA, the Tokyo VAAC reported that an explosion at Suwanose-jima on 15 December at 1946 produced a plume to an unknown height.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


11 September-17 September 2002

Activity at Suwanose-jima was relatively low from 26 August until 12 September. On the 12th explosive eruptions began to occur frequently. According to the Suwanose-jima office of Toshima village, rumbling was intermittently heard about 4 km SSW of the summit and small amounts of ash fell. Explosions continued to occur until at least 13 September.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


21 August-27 August 2002

Eruptive activity began to decline at Suwanose-jima in comparison to the previous week. Periods of volcanic tremor occurred on the 19th and 20th. According to the Suwanose-jima office of Toshima Village, rumbling sounds were not as strong as those of the previous week, but were sometimes accompanied by the sounds of large explosions on the 20th. Small amounts of ash fell in inhabited areas about 4 km SSW of the summit on the 20th and 21st. On the afternoon of the 20th ash also fell in Naze city on Amami-oshima Island, about 140 km S of Suwanose-jima. Aerial inspections conducted during the report period by the staff of Kagoshima Meteorological Observatory revealed that an ash-rich cloud rose 1.5 km above the crater and drifted S.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


14 August-20 August 2002

Small explosive eruptions occurred at Suwanose-jima on 19 August. JMA reported that on the 19th two periods of continuous acoustic signals were recorded for 20-30 minutes each beginning around 0000 and 0630. The signals were the largest recorded thus far this year. Explosions and rumbling were heard from Toshima village, and an ash plume drifted to the SW. Volcanic tremor with continuous large acoustic signals was also recorded later in the day during 0940-0950 and 1410-1500. Small tremor events also occurred, and ash rose above the summit to an unknown height and drifted SE.

Sources: Japan Meteorological Agency (JMA) via the Volcano Research Center; Kyodo News; Associated Press


12 June-18 June 2002

Based on information from aircraft reports and JMA, the Tokyo VAAC stated that volcanic ash from Suwanose-jima was reported on 18 June at 1058 at a height of ~6 km drifting E. Ash was not visible on satellite imagery.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)


17 October-23 October 2001

On 11 October at 1400 an eruption began at Suwanose-jima. Volcanic tremor associated with the eruption was detected during 11 October through at least 15 October. Up to eleven explosions were counted. Acoustic microphones recorded four shock waves associated with large explosions.

Sources: Volcano Research Center-Earthquake Research Institute (University of Tokyo); Japan Meteorological Agency (JMA)


25 July-31 July 2001

Volcanic tremor was detected near Suwanose-jima's On-take (Otake) crater beginning on 25 July at 2200 until at least 26 July. JMA reported that an eruption on 26 July at 1430 produced a volcanic plume that rose to 1.3 km above the crater and drifted to the S. That day seismometers ~2 km SW of the crater recorded explosions at 0501, 0558, 0935, and 1055. According to the Suwanose-jima Branch of the Toshima Village Office, ash fell the morning of 26 July.

Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)


9 May-15 May 2001

Beginning on the morning of 9 May volcanic activity increased at Suwanose-jima when a tremor event commenced. The tremor increased at 1100 and became more violent at 2100. Around noon on 11 May an eruption produced an ash cloud that rose 1-1.5 km above the crater. The Suwanose-jima Branch of Toshima village, ~4 km NNW of the active On-take (Otake) crater, reported that abundant ash fall was observed in the village on 11 May. Vigorous eruptions on the evening of 12 May and the morning of 13 May deposited up to 3 cm of ash in the village. At 0900 on 14 May the eruption seemed to have stopped. The Sakurajima Volcano Observatory reported that plumes associated with volcanic tremor events have been observed at Suwanose-jima since the new crater was formed during the December 2000 eruption.

Sources: Volcano Research Center-Earthquake Research Institute (University of Tokyo); Tokyo Volcanic Ash Advisory Center (VAAC)


17 January-23 January 2001

At ~1700 on 19 December 2000, a Suwanose-jima inhabitant reported "smoke" rising NE of the summit crater. During observations from a helicopter, ash-laden smoke and high-temperature gas emissions were seen emanating from new craters. The Sakura-jima Volcano Research Center observed an increase in volcanic earthquakes deeper than 1 km below the summit in comparison to Fall 1999. They also noted an increase in volcanic earthquakes and tremor shallower than 1 km in comparison to early 2000. Researchers will continue to closely monitor the volcano.

Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)


Index of Bulletin Reports


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.

06/1970 (CSLP 53-70) Summit-crater explosions on 28 May

01/1971 (CSLP 53-70) Explosions on 13 and 20-22 December 1970

06/1976 (NSEB 01:09) Mild Strombolian eruptions continue

09/1976 (NSEB 01:12) Pilots note unusually high "smoke" columns

05/1977 (NSEB 02:05) Frequent explosions and considerable ashfall

06/1977 (NSEB 02:06) Explosions continue but are less frequent

08/1977 (NSEB 02:08) Eruptions continue; considerable ash deposition

10/1977 (NSEB 02:10) Activity continued during August and September

08/1979 (SEAN 04:08) Activity since January 1977 tabulated

09/1979 (SEAN 04:09) Six hours of explosions; air shocks rattle doors and windows 90 km away

01/1980 (SEAN 05:01) Explosions; incandescent tephra; 1979 activity summarized

07/1980 (SEAN 05:07) Tephra ejection

12/1980 (SEAN 05:12) December 1979-December 1980 explosions tabulated

10/1981 (SEAN 06:10) January-August 1981 explosions tabulated

11/1981 (SEAN 06:11) Three days of explosions

11/1982 (SEAN 07:11) November 1981-October 1982 activity

03/1984 (SEAN 09:03) Summary of activity, November 1982-January 1984

07/1985 (SEAN 10:07) Explosions resume; 2.5 km plume; ashfall 25 km SE

07/1986 (SEAN 11:07) Explosions cause 200 m plume

11/1986 (SEAN 11:11) 500-600-m-high ash plume

01/1987 (SEAN 12:01) Plume to 1,200-1,500 m

05/1987 (SEAN 12:05) Ash eruption

04/1988 (SEAN 13:04) Small explosions; light ashfall

07/1988 (SEAN 13:07) 3,000-m ash cloud

10/1988 (SEAN 13:10) Plume seen from aircraft

03/1989 (SEAN 14:03) Explosions and ashfall; 1988 activity summarized

06/1989 (SEAN 14:06) Frequent explosions; ashfall on inhabited area

07/1989 (SEAN 14:07) Vigorous explosions continue

12/1990 (BGVN 15:12) Explosions and ash emissions

10/1991 (BGVN 16:10) Ash ejection

05/1992 (BGVN 17:05) Tephra clouds from frequent explosions

10/1992 (BGVN 17:10) Explosions eject blocks

11/1992 (BGVN 17:11) Frequent explosions; lava fountains

03/1993 (BGVN 18:03) Sporadic, weak ash eruptions

04/1993 (BGVN 18:04) Sporadic, weak ash eruptions

05/1993 (BGVN 18:05) Weak ash explosions

08/1993 (BGVN 18:08) Eruption produces ashfall up to 100 km away

12/1993 (BGVN 18:12) Small explosive eruptions

12/1994 (BGVN 19:12) Intermittent weak eruptions throughout 1994 cause ashfall on the island

12/1995 (BGVN 20:11) Continued minor eruptive activity throughout much of 1995

01/1996 (BGVN 21:01) Small eruptions in January; nine explosions throughout 1995

03/1996 (BGVN 21:03) Weak ash eruptions in early March cause ashfalls

06/1996 (BGVN 21:06) Strong eruptions produce volcanic ash clouds

07/1996 (BGVN 21:07) Explosive activity continues

01/1997 (BGVN 22:01) Weak ash emission and rumbling in late December

06/1997 (BGVN 22:06) Ashfall in March and continued ash emissions in April

02/2001 (BGVN 26:02) Two subsidiary craters discovered; elevated activity in December 2000

07/2001 (BGVN 26:07) Explosive eruptions in May and July

07/2002 (BGVN 27:07) Volcanic tremor, plumes, and ash eruptions during October 2001-August 2002

04/2003 (BGVN 28:04) Ash explosions in September and December 2002, and activity in January 2003

03/2004 (BGVN 29:03) Sporadic eruptions in 2003 and in January 2004, one to 2.4 km altitude

07/2005 (BGVN 30:07) Eruptions during April 2004-July 2005 send plumes to varying heights

11/2007 (BGVN 32:11) Eruptions of July 2005-December 2007 send plumes to varying heights

02/2008 (BGVN 33:02) Small (~1 km) plumes noted during late 2007-early 2008

09/2008 (BGVN 33:09) Eruption continues from 2007 into 2008

07/2009 (BGVN 34:07) Explosive eruptions continue through 6 July 2009

07/2011 (BGVN 36:07) Many small explosions up to 2 km altitude during mid-2009 to mid-2011

08/2012 (BGVN 37:08) 2011-2012 eruptions with plumes rising up to 1 km above crater rim

04/2013 (BGVN 38:04) Near continuous tremor between July 2012 and March 2013




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


06/1970 (CSLP 53-70) Summit-crater explosions on 28 May

Card 0958 (10 June 1970) Summit-crater explosions on 28 May

"On-take, the summit crater of Suwanose-zima volcano exploded with large explosion sounds at 0000-0050 JST on 28 May 1970. Explosions took place with frequency of about three times a minute. Volcanic smoke at 0730 JST was 2,000-3,000 m high and these activities became quiet at about 0800 JST.

Information Contacts: Y. Sawada, Seismological Division, JMA, Tokyo, Japan.

01/1971 (CSLP 53-70) Explosions on 13 and 20-22 December 1970

Card 1095 (20 January 1971) Explosions on 13 and 20-22 December 1970

The summit crater of On-take peak exploded on the 13th and on the 20th to 22nd of December 1970. During these explosions, volcanic smoke continuously went up about 1,000 m high.

Information Contacts: Y. Sawada, Seismological Division, JMA, Tokyo, Japan.

06/1976 (NSEB 01:09) Mild Strombolian eruptions continue

Mild Strombolian eruptions continued, with smoke columns reaching heights of 100-1,000 m, rumblings and occasional ash falls.

Information Contacts: Japan Meteorological Agency (JMA), Tokyo.

09/1976 (NSEB 01:12) Pilots note unusually high "smoke" columns

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.

    1975       Plume     Activity
             Height (m)

    Oct 04      700      Sometimes moderate explosions
        05     1000      Sometimes large explosions, ashfall
        06     1500      Large explosions, ashfall
        07      --       Explosion
        08     1000      Large explosion
        09      500      Explosion
    Nov 09     1500      Large explosion
        10      600      Explosion
        19      500      Large explosion
    Dec 07      200      Sometimes small explosions
        21      700      Frequent large explosions
        21      400      Remarkable incandescent column, frequent large
                           explosions
        23      700      Explosion
        24      400      Sometimes large explosions
        25      700      Explosion
        26     1000      Frequent large explosions
        27      700      Large explosion
        28      700      Moderate explosion
        31      400      --

    1976
    Jan 08      300      Large explosion
        24     1000      Ashfall
        25     1000      Large explosion, ashfall
        26      --       Ashfall
        27      500      Large explosion, ashfall
        28-29  1500      --
    Feb 14      --       Moderate explosion
        15      800      Moderate explosion, ashfall
        16      --       Sometimes explosion sounds, ashfall
        17      --       Sometimes explosion sounds
        18      300      Sometimes explosion sounds
        19      700      Explosion
        20      500      Moderate explosion
        26      --       Explosion
    Mar 12      500      Frequent large explosions
        13      700      Frequent large detonations
        14      500      Sometimes moderate explosions
    Apr 13      --       Moderate detonation
        14      300      Ashfall
        15      300      Ashfall, moderate explosion
        16     1000      Ashfall
    May 10      500      Explosion
    Jul 03     4200      Moderate detonation
        04   3600-4200   TOA airline pilot observed ashcloud
        07     3600      TOA airline pilot observed ashcloud
        23     3000      Explosion, large ash cloud, ashfall
        24     3000      Explosion, ashfall
    Oct 04      500      Ashfall
        12      500      Ashfall
    Nov 01      --       Ashfall

    1977
    Jan 11     1200      One explosion
    Mar 19-21   700      Ash ejection and ashfall
        24-25   --       Two explosions
    Apr 01-03  1000      One explosion, ash ejections
        10-11  3000      Ash ejections and ashfall
        14-20  1000      Two explosions, ash ejections & ashfall
        27-29  3000      Explosions, ash ejections
    May 08      --       One explosion
        13-18  2000      Several explosions, ashfall
        26     1000      One explosion
    Jun 03-05  3000      Frequent explosions, incandescent column, ashfall
        21-22  3000      Frequent explosions
    Jul 09-10  4000      Ash ejections, one explosion
        23      --       Explosions
    Aug 08-10  3000      Frequent explosions, incandescent ejecta
    Sep 10-15  3000      Frequent explosions, ash ejections, ashfall
        18     3000      Ash ejections and ashfall
    Oct 23     1000      One ash ejection
        26-30  2000      Ash ejections
    Nov 14      --       One explosion
        19     2000      Ash ejections
    Dec 06      --       One explosion

    1978
    Jan 23      --       Three explosions
    Mar 19      500      Two ash ejections
        22-25  1000      Ash ejections
    Apr 09     1000      Ash ejections
        19-22  3000      Ash ejections and ashfall
    May 01-03   500      Ash ejections and ashfall
        31      500      Frequent explosions, incandescent column
    Jun 01      500      Frequent explosions, incandescent column, ashfall
        16-19   --       Frequent explosions
    Jul 02-05   700      Frequent explosions, incandescent column, ashfall
        19-21  3000      Ash ejections and ashfall
    Aug 07-10  3000      Frequent explosions, incandescent column, ashfall
        24     2000      Ash ejections and ashfall
    Sep 07     3000      Frequent explosions, ashfall
        17      --       One explosion
        23-24   700      Frequent explosions, incandescence
    Oct 10-12  5000      Frequent explosions, ashfall
        24-28  3000      Frequent explosions, incandescence, ashfall
    Nov 06-10   700      Explosions, incandescence, ashfall
        19-22   500      Explosions, incandescent column, ashfall
    Dec 04-05   300      Explosions

    1979
    Feb 06      500      Explosions, incandescence
        14-15   500      Explosions, ashfall
        19      500      One explosion
        22      --       One explosion
    Mar 11-13   500      Four explosions
    Jun 05      --       Incandescent column, explosions
    Jul 20      500      Seven explosions, ash emissions
        21      200      Ash emissions
    Sep 05-06  2000      Frequent, strong explosions, incandescent columns,
                           ashfall to sea
        07     1000      Ash emissions
        08      800      Ash emissions
        09     2000      Frequent explosions
        12     1000      Ten explosions
    Dec 10     1500      Explosions, incandescent blocks, reflected glow
        11      --       Ash emissions
        12      --       "Flames" in crater
        18      300      Three explosions

    1980
    Feb 05-06  1500      About 10 explosions, incandescent column
    Mar 21-22  1000      Many explosions
    Apr 25-26  1500      Explosions: ashfall on inhabited areas
    May 13      --       Three explosions
        18      500      Six explosions; persistent ash ejection
    Jun 04-05   500      More than 25 explosions
    Jul 16-19   --       Many explosions
    Aug 03-08  1500      Several tens of explosions; incandescent column
        21-23  1000      More than 20 explosions; incandescent column
    Sep 08-09  1000      More than 1000 explosions
        20      --       Three explosions
        24-27  2000      More than 1000 explosions
    Oct 25-27   500      Persistent ash ejection
    Nov 08-10  1500      More than 1000 explosions
        29      500      Persistent ash ejection
    Dec 13      --       Explosions

    1981
    Jan 04-08  100-1000  Continuous ash cloud
        29      500      Ten explosions
        30      300      Two explosions
        31      NVO      Two explosions
    Feb 12     1000      One explosions
        20     1000      Three explosions
        26      500      16 explosions
    Mar 17     1000      20 explosions
    Apr 15      NVO      Many explosions
        16      NVO      16 explosions
        26      500      Many explosions
    May 14      500      Ten explosions
    Jun 12     1500      Three explosions
        13      NVO      Two explosions
        15      NVO      Three explosions
        16      NVO      Three explosions
        29-30   --       Many explosions
    Jul 01-04   NVO      Many explosions
        05      500      Ten explosions
        06      NVO      Ten explosions
        13      NVO      Three explosions
        14     2000      Many explosions
        15      NVO      Six explosions
    Nov 26      NVO      Many explosions
        27     1500      Many explosions
    Dec 13      500      40-50 explosions; rumbling
        14      500      Many explosions; rumbling
        15      500      30-40 explosions; rumbling
        16      500      Two explosions
        23      NVO      Two explosions

    1982
    Jan 02     1500      Four explosions
        23     1000      2-3 explosions/hour
        25      200      Ten explosions
        26      500      Many explosions
        27      300      12 explosions
        28      300      Three explosions
    Feb 03      NVO      Five explosions
        06      200      Five explosions
        07      200      One explosion
        08      200      One explosion
        13     1000      One explosion; rumbling
        14-15   500      Many explosions; rumbling
        16-17   NVO      Many explosions; rumbling
        18      500      Many explosions; rumbling
        19      NVO      Six explosions
        22     1000      Three explosions
        23      NVO      Four explosions
        24      NVO      Three explosions
        25     1000      Seven explosions; rumbling
        26      500      Five explosions
    Mar 09     1000      Many explosions; rumbling
        10     1000      Many explosions; rumbling
        11      500      Ten explosions
        28      NVO      Ten explosions; rumbling
        29      NVO      20-25 explosions; rumbling
        30     1000      Four explosions
        31      NVO      Six explosions
    Apr 01     1000      Two explosions
        02     1000      Ten explosions
        03      NVO      Three explosions
        15      500      18-20 explosions; rumbling
        17      500      5-6 explosions/hour
        18      NVO      2-3 explosions/hour
        19      NVO      Ten explosions; rumbling
    May 05      200      One explosion
        06     1000      Many explosions; rumbling
        27     1000      One explosion
    Jun-Jul     NVO      Quiet
    Aug 16     1000      Four explosions
        17      500      Four explosions
    Sep 02      500      Five explosions
        16      NVO      Many explosions
        25      200      Nine explosions
        26      200      Three explosions
    Oct 05      500      Three explosions; rumbling
        06      NVO      Six explosions
        07      NVO      Seven explosions
        08      NVO      Ten explosions; rumbling
        09      300      Seven explosions
        17      NVO      One explosions
    Nov 03      500      3-4 explosions/hour       (0500-2200 LT)
        04      500      5-6 explosions/hour       (0500-2200 LT)
        05      500      5-6 explosions/hour       (0700-2100 LT)
        06      500      3 explosions/hour         (0500-2200 LT)
        07      500      1-2 explosions/hour       (0600-2200 LT)
        23      500      Five explosions           (0900-1300 LT)
    Dec 15      500      Ashfall
        17     1000      15-16 explosions          (1300-2000 LT)
        18      500      Ashfall
        19     1000      2-3 explosions/minute     (0900-2100 LT)
        20     1000      1-2 explosions/5 minutes  (0600-2100 LT)
        29      500      Two explosions            (1000-1300 LT)

    1983
    Jan 17      500      4-6 explosions/minute     (0630-0800 LT)
                         3-4 explosions/hour       (0800-2000 LT)
        18    Unknown    3-5 explosions/hour       (0600-2200 LT)
        19    Unknown    15-20 explosions          (0600-1700 LT)
        28      500      25-30 explosions          (1700-2200 LT)
        29      700      2-3 explosions/minute     (0500-1800 LT)
                         4-5 explosions/hour       (1800-2200 LT)
        30     1000      4-5 explosions/hour       (0500-1600 LT)
    Feb 10      200      A few explosions
        11      500      1-2 explosions/minute     (1900-2100 LT)
        26     1000      5-6 explosions/minute     (1530-2300 LT)
        27     1000      Ten explosions            (0500-1200 LT)
    Mar 04    Unknown    One explosion
        11     1000      2-3 explosions/minute     (1400-2300 LT)
        12    Unknown    12 explosions             (0600-1200 LT)
        13      --       Three explosions          (0800-1200 LT)
    Apr 28    Unknown    3-5 explosions/minute     (1400-1600 LT)
        29      500      Three explosions          (1500-1900 LT)
    May 08      200      Six explosions            (0700-1500 LT)
        11      200      Three explosions          (1400-1500 LT)
        12      200      Three explosions          (1300-1500 LT)
    Jun 08     1500      Seven explosions          (1400-1900 LT)
        09     1500      Four explosions           (1500-1800 LT)
        10      500      Seven explosions          (0900-2000 LT)
    Jul 05-06   --       Incandescent column       (2100-0300 LT)
        27      500      Two explosions            (1200-1730 LT)
    Sep 30     1500      7-9 explosions/hour       (0500-0900 LT)
    Oct 01     1000      17 explosions             (0500-0900 LT)
        17    Unknown    15 explosions             (0600-1800 LT)
        18     1000      Five explosions           (0530-1130 LT)
        27      500      Rumbling                  (1400-2300 LT)
        28     1000      Rumbling                  (0500-1330 LT)
        29     1000      Rumbling                  (0500-  ?  LT)
    Nov 22      500      10-15 explosions/minute   (1000-2200 LT)
        23      500      15-20 explosions/minute   (0920-1100 LT)
                         15-20 explosions/minute   (1400-1700 LT)
        25      300      16 explosions             (0600-1800 LT)
    Dec 03      500      2-10 explosions/minute    (1500-2300 LT)
        04      300      Six explosions            (1000-2200 LT)
        18      500      2-3 explosions/minute     (0400-1500 LT)
                         10 explosions             (1500-2200 LT)
        19      500      15-20 explosions/minute   (0500-0900 LT)
                         20 explosions             (1500-2300 LT)
        20      500      2-3 explosions/minute     (0400-0700 LT)
                         20 explosions             (0700-2100 LT)

    1984
    Jan 02      300      13 explosions             (0500-2000 LT)
        26      300      13 explosions             (0600-2200 LT)
        27      500      5-7 explosions/hour       (1600-2200 LT)
        28      500      30-40 explosions/hour     (0800-2300 LT)
        29      500      Seven explosions          (0500-1200 LT)
        30      500      10 explosions             (0400-1500 LT)
    Mar 14-16   --       4-5 explosions/minute
        18      --       10 explosions             (0500-2300 LT)
    Apr 12     1000      Seven explosions          (2100-2300 LT)
        15      --       Seven explosions          (0730-1300 LT)
                         5-6 explosions            (1700-2200 LT)
        16      --       Six explosions            (0700-1700 LT)
        17      --       12 explosions             (0500-1000 LT)
        18      --       Three explosions          (0600-1000 LT)
    May 15      --       12-13 explosions

    1985
    Jun 28     2000      Airplane pilot saw the ash cloud,
                           light ashfall
    Aug 03      --       Airplane pilot saw the ash cloud
    Sep 14-15   --       Frequent explosion sounds
    Oct 01      --       Airplane pilot saw the ash cloud
    Nov 17-21   --       Frequent explosion sounds
    Dec 05-06   --       Frequent explosion sounds

Information Contacts: JMA, Tokyo.

05/1977 (NSEB 02:05) Frequent explosions and considerable ashfall

Frequent explosions from the summit crater occurred 26-29 April (table 1). Considerable ash fell nearby from eruptive clouds that rose 3,000 m above the vent. Explosion sounds and air shocks were often detected and glow was seen on one or two occasions.

Information Contacts: JMA, Tokyo.

06/1977 (NSEB 02:06) Explosions continue but are less frequent

Strombolian activity continued into May, but explosions were less frequent.

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

08/1977 (NSEB 02:08) Eruptions continue; considerable ash deposition

Eruptions from On-take summit crater continued through July, with ash clouds rising 2,000-3,000 m and considerable ash deposition.

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

10/1977 (NSEB 02:10) Activity continued during August and September

Strombolian activity continued during August and September. An eruption at 1000 on 14 September produced clouds that rose 2,000 m above On-take.

Information Contacts: JMA, Tokyo.

08/1979 (SEAN 04:08) Activity since January 1977 tabulated

Activity has been observed only once since mid-March (table 1), in contrast to the pattern of the preceding 26 months. From January 1977-March 1979 there were 1-4 periods of tephra ejection per month, each lasting up to a few days.

Information Contacts: JMA, Tokyo.

09/1979 (SEAN 04:09) Six hours of explosions; air shocks rattle doors and windows 90 km away

"On-take vent exploded on 5 September, after a few small explosions on 20 July (table 1). Explosive activity continued from about 2000 on 5 September to 0100 on 6 September. Incandescent columns rose 500 m above the crater and explosions occurred every 10 seconds during the most active stage on the 5th. Explosive sounds (rumblings) were heard at Yaku-shima Island, 90 km NE of Suwanose-jima, and windows and doors on Yaku-shima were rattled by air vibrations. Ash fell in the sea E of Suwanose-jima.

"A village of 65 people lies on Suwanose-jima Island. People there said that the activity on 5 September was one of the strongest of the many explosive periods since 1956. No damage was caused by the explosions. Explosions at the volcano had become less frequent this year than before."

Information Contacts: JMA, Tokyo.

01/1980 (SEAN 05:01) Explosions; incandescent tephra; 1979 activity summarized

A loud explosion from On-take summit crater occurred at about 0700 on 10 December, after three months of quiescence. The initial explosion produced a 1.5-km-high cloud, and smaller explosions continued for about 3 hours. Ash clouds then decreased, but ejections of incandescent material and reflected glow were seen that night. Activity decreased further to weak ash emission the next day, although glow in the summit crater were seen from the air on 12 December. The explosions caused no damage on the island.

Information Contacts: JMA, Tokyo.

07/1980 (SEAN 05:07) Tephra ejection

Aerial observers reported that tephra clouds rose to about 1.8 km above On-take vent on 18-19 May.

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

12/1980 (SEAN 05:12) December 1979-December 1980 explosions tabulated

Strombolian explosions have occurred almost every month since November 1956 from On-take, the highest point on Suwanose-jima Island. Eruptive activity has typically lasted from one to a few days. The only damage from the 1980 explosions (table 1) was caused by minor ashfalls on crops. Between explosive periods, white vapor rose a few hundred meters above the vent.

Information Contacts: JMA, Tokyo.

10/1981 (SEAN 06:10) January-August 1981 explosions tabulated

During 1981, explosions from Suwanose-jima have been recorded every month through August. Observations were made from 3 km S of the active B crater (figure 1) and from Nakano-shima Island, 26 km NE. An explosion is registered when visual observation of an eruption cloud is correlated with the sound of an explosion. Aircraft crews reported three eruption clouds: 28 June, cloud height 1.2 km; 17 July, 2.4 km; and 10 August, 2.7 km.

Figure 1. Topographic map of Suwanose-jima Island; the active vent is in Crater B. Courtesy of JMA.

Information Contacts: JMA, Tokyo.

11/1981 (SEAN 06:11) Three days of explosions

After two months of quiesence, Crater B was active 25-28 November. Ash was ejected on 25 November. Explosive sounds were recorded from about 0200 on the 26th. Activity intensified to register 5-6 explosions/minute from 1230 to 1700 that day, then declined to about 10/hour. From 1700 on the 27th to 0200 on the 28th about four explosions/hour were recorded. On 28 November activity was limited to continuous emission of white vapor. The ash and blocks ejected during the activity caused no damage.

Information Contacts: JMA, Tokyo.

11/1982 (SEAN 07:11) November 1981-October 1982 activity

No damage was reported from 1982 activity, but there was heavy ashfall on the inhabited, S end of the island on 7 October. The eruptive activity typically lasted from one to a few days. Between active periods, white vapor rose a few hundred meters above the vent.

Information Contacts: JMA, Tokyo.

03/1984 (SEAN 09:03) Summary of activity, November 1982-January 1984

Strombolian activity has been recorded almost every month, November 1982-January 1984 (table 1). No damage was reported, although there were often heavy ashfalls on the inhabited area of the island, along the shore 3.5 km SSW of the active vent.

Information Contacts: JMA, Tokyo.

07/1985 (SEAN 10:07) Explosions resume; 2.5 km plume; ashfall 25 km SE

Occasional Strombolian activity continued until May 1984, but no explosion sounds had been reported since June (table 1). During the afternoon of 28 June 1985, an aircraft pilot flying near Suwanose-jima saw a plume rising to an altitude of 2-2.5 km (table 1). At Nakano-shima, about 25 km NE of the volcano, slight ashfall was observed, but no explosions were heard.

Information Contacts: JMA, Tokyo.

07/1986 (SEAN 11:07) Explosions cause 200 m plume

Explosive sounds were heard . . . twice on the morning of 28 July, and a 200-m-high plume was observed from an airplane at around 1200.

Information Contacts: JMA.

11/1986 (SEAN 11:11) 500-600-m-high ash plume

On 2 October, observers aboard a Nihon Kinkyori Airways plane saw the volcano emitting a white plume to ~500-600 m height. An ash plume was sometimes seen from 30 km NE of the summit (in Nakanoshima) by the JMA Mobile Volcanological Observation Team.

Information Contacts: JMA.

01/1987 (SEAN 12:01) Plume to 1,200-1,500 m

An airplane pilot saw a plume rising to 1,200-1,500 m altitude at 1318 on 11 December.

Information Contacts: JMA.

05/1987 (SEAN 12:05) Ash eruption

On 24 April, an airplane pilot saw an ash plume rising to 3,000 m altitude.

Information Contacts: JMA.

04/1988 (SEAN 13:04) Small explosions; light ashfall

Small explosions were heard by residents of the island at a rate of 5-6/day between 0500 and 1500 on 13 April. Ash plumes rose 500-600 m, sometimes accompanied by roaring sounds or air shocks. On 15 April, continued 500-600-m-high ash emission began at 0530. A Japan Air System (formerly TDA airline) pilot saw an ash cloud moving S at 1,800-2,100 m altitude (1,000-1,300 m above the summit) at 0848. A light ashfall was observed at a harbor on the island, but no explosions were heard and no air shocks were felt that day. No explosions were reported the following day.

Information Contacts: JMA.

07/1988 (SEAN 13:07) 3,000-m ash cloud

At 1430 on 18 July, a Southwest Airlines crew observed a 3,000-m-high ash cloud.

Information Contacts: JMA.

10/1988 (SEAN 13:10) Plume seen from aircraft

A jetliner crew observed a 2.0-km-high plume . . . on 9 August at 1630.

Information Contacts: Y. Sawada, JMA; D. Shackelford, Fullerton, CA.

03/1989 (SEAN 14:03) Explosions and ashfall; 1988 activity summarized

On 1, 14, and 16 January, residents . . . heard explosions. Ash fell to the S on 21 and 24 January in the the only inhabited part of the small island. On 7 February at 1225, an explosion sound was heard, and on 28 February, a 1,000-m-high ash plume deposited large amounts of ash to the S. At 1640 on 3 March, the crew of a JAS aircraft observed a 2,000-m ash cloud. A summary of [1987-88] explosions and ashfall is shown in table 2.

Table 2. Eruptive episodes at Suwanose-jima, January 1987-October 1988. Courtesy of JMA.

    1988       Plume     Activity
             Height (m)

    Jan 05       --      Four explosions
        16      300      Five explosions
        17      500      Four explosions
        18      300      One explosions
    Feb 29       --      Explosion at 1325 caused air shock
    Mar 08      500      Eleven explosions accompanied by air shock
        28       --      Three explosions accompanied by air shock
    Apr 13      500      Five or six explosions per minute
        14      500      40-50 explosions
        15     2000      TOA Domestic Airlines pilot saw the plume
                           rising 2000 m
        16      500      Ashfall in the S part of the island
    Jul 18     3000      Southwest Airlines pilot saw the ash plume rising
    Aug 09     2000      Japan Air System pilot saw the plume rising 2000 m
        13      500      Ashfall in the S part of the island
        29      300      Several explosions, ashfall
    Oct 03      500      Ashfall in the S part of the island
        06       --      Rumbling, ashfall in the S
        07       --      Rumbling, ashfall in the S

Information Contacts: JMA.

06/1989 (SEAN 14:06) Frequent explosions; ashfall on inhabited area

. . . March-April activity is summarized in table 2. No explosions were observed in May, but several tens of explosions 22-23 June were accompanied by detonations and air shocks. Ash fell on the S part of the small island volcano, in the only inhabited area.

Information Contacts: JMA.

07/1989 (SEAN 14:07) Vigorous explosions continue

Explosions continued at Suwanose-jima. On 22 and 23 June 1989, several tens of eruptions were reported, accompanied by audible detonations, felt air shocks, and ashfalls on the inhabited S side of the island.

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

12/1990 (BGVN 15:12) Explosions and ash emissions

Eruptive activity was weak in the first half of 1990, but explosions became frequent in late July, and activity was most vigorous in October and November. The highest ash cloud (1,500 m) was observed, and ash-related agricultural damage was reported, in late October. Glow from the most active crater . . . was seen at night on 27 October and 10-15 November.

Information Contacts: JMA.

10/1991 (BGVN 16:10) Ash ejection

Late-October explosions from the summit cone of On-take produced ash clouds a few hundred meters high and caused slight ashfalls on the island. The explosions were the most vigorous since similar events in January.

Information Contacts: JMA.

05/1992 (BGVN 17:05) Tephra clouds from frequent explosions

Island residents reported frequent explosions, ashfalls, and rumbling in early and mid-May. Ash plumes were observed rising to 1.5-2.0 km elevation by Japanese airline pilots on 1-3 May, and a plume was visible on a NOAA weather satellite image at 1538 on 1 May.

Recently, the volcano had been active several times a year, with frequent explosions producing ash clouds and detectable ashfall. During peaks in activity, ash clouds rose to 2-3 km height and tens of small explosions occurred per minute. Eruptive episodes typically lasted for a few days to a month. Explosions had been reported earlier in 1992 on 1-4, 10, and 25-31 January, 4-14 and 21-28 February, 2-4 and 11-12 March, and 15-16 April.

Information Contacts: JMA; W. Gould, NOAA.

10/1992 (BGVN 17:10) Explosions eject blocks

Island residents reported an increase in activity on the morning of 20 October. Rumbling was heard at 2230 and frequent detonations began the following morning. Numerous blocks were ejected on 22 October with explosive activity decreasing after the 23rd. Explosions in 1992 had been reported 1-3 times a month through May, and on 2 June, 9-10 July, 21-24 September, and 11 October.

Information Contacts: JMA.

11/1992 (BGVN 17:11) Frequent explosions; lava fountains

Explosive activity . . . ended by 4 November. Additional explosive activity with frequent detonations occurred on 19-22 November. Incandescent lava fountains were observed on the night of 21 November. No damage resulted.

Information Contacts: JMA.

03/1993 (BGVN 18:03) Sporadic, weak ash eruptions

Sporadic, weak ash eruptions [in March] resulted in slight ashfall on inhabited areas . . . .

Information Contacts: JMA.

04/1993 (BGVN 18:04) Sporadic, weak ash eruptions

Sporadic, weak ash eruptions continued in April. The island's residents heard explosions [during] 22-26 April.

Information Contacts: JMA.

05/1993 (BGVN 18:05) Weak ash explosions

Island residents observed weak ash eruptions and heard explosions in late May.

Information Contacts: JMA.

08/1993 (BGVN 18:08) Eruption produces ashfall up to 100 km away

Eruptive activity in mid-August caused ashfall on this island and on other islands 100 km NE. Pilots from six domestic airlines reported ash clouds up to 3 km above sea level near the volcano on 14-18 August. Seismic monitoring equipment on the island detected no unusual activity.

Information Contacts: JMA.

12/1993 (BGVN 18:12) Small explosive eruptions

Weak ash eruptions were observed and explosions were heard by island residents through December 1993 following eruptive activity in mid-August . . . .

Information Contacts: JMA.

12/1994 (BGVN 19:12) Intermittent weak eruptions throughout 1994 cause ashfall on the island

Weak ash eruptions were observed and explosion sounds were heard by local residents throughout 1994. Heavy ash sometimes fell in a village on the island. Occasional ash emissions occurred in mid-February, with ashfall reported on the 11th. Emissions began again in mid-March, with ash falls on the island on 19 and 27 March. The next month, ash eruptions took place on 3-4 and 30 April. Frequent ash ejections during 8-12 May also caused ashfall on the island; detonations were heard on the 8th. Ash ejections were again observed on 14-21 and 29-30 July, with ashfall on the 15th and 20th. Detonations and ashfall were again reported on 12 August. Ashfall was frequent in September and the second half of October, with larger volumes on 13-14 and 31 October. Ash emission in December was observed at the beginning and end of the month, with ashfall on 1-4 and 31 December; rumbling was heard the night of the 3rd.

Information Contacts: JMA; Y. Sawada, JMA; D. Shackleford, Fullerton, CA.

12/1995 (BGVN 20:11) Continued minor eruptive activity throughout much of 1995

Eruptive activity took place from March to June and from August to December 1995. Some ashfalls were observed at a village 4 km SSW of the crater. The two historically active summit craters and typically have Strombolian eruptions.

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

01/1996 (BGVN 21:01) Small eruptions in January; nine explosions throughout 1995

Monitoring from the Sakurajima Volcanological Observatory revealed nine explosions from Suwanose-jima in 1995. According to the Japan Meteorological Agency and the Kagoshima Prefectural Government, small eruptions during 10-13 January 1996 sent plumes 300-600 m above the volcano and caused ashfall to the S. Activity has been high since 1950, with 1-2 ash emissions every month, and some Strombolian explosions.

Information Contacts: Volcano Research Center, Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan (URL: http://hakone.eri.u-tokyo.ac.jp/vrc/vrc.html).

03/1996 (BGVN 21:03) Weak ash eruptions in early March cause ashfalls

Weak ash eruptions were observed on 5 and 6 March; occasional ashfalls were reported on the island. Nine explosions were observed in 1995 and there were small eruptions during 10-13 January (BGVN 21:01). Activity has been high since 1950.

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

06/1996 (BGVN 21:06) Strong eruptions produce volcanic ash clouds

On 2 June, an aviation notice to airmen (NOTAM) indicated a volcanic ash cloud to 4,600 m emanating from Suwanose-jima. A second NOTAM at 1515 on 2 June noted that the ash cloud top was at 2,100 m. No discernible ash plume was evident in GMS satellite data from the Japanese Meteorological Agency (JMA) through 1732 on 2 June.

The Kagoshima Prefectural Government confirmed to JMA that emissions on 1-2 June caused ashfall. Ashfall was also observed on the island on 4 June.

The Sakura-jima Volcanological Observatory of Kyushu University reported that activity has continued at the same level since 1994, with nearly constant A-type earthquakes. Ash emissions have occurred this year on 10-13 January, 23 February, 5-6 March, and 14 April. The eruption column in March rose 500 m above the volcano.

Information Contacts: Volcano Research Center, Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan (URL: http://hakone.eri.u-tokyo.ac.jp/vrc.html); Jim Lynch, NOAA/NESDIS Synoptic Analysis Branch (SAB), Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA; Volcanological Division, Japan Meteorological Agency, 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan.

07/1996 (BGVN 21:07) Explosive activity continues

According to Kagoshima Prefectural Government, a weak ash eruption was observed on 14 July. On 22 July a civil aviator reported an ash cloud at ~1.5 km altitude.

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

01/1997 (BGVN 22:01) Weak ash emission and rumbling in late December

On 26, 27, and 28 December, the Government of the Kagoshima Prefecture reported weak ash emission and rumbling from Suwanose-jima. A small quantity of ashfall was observed on 27 December.

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

06/1997 (BGVN 22:06) Ashfall in March and continued ash emissions in April

An ash column 500-600 m high above the summit resulted in ashfall starting at about noon on 24 March and continuing until the evening of the following day. Ash emissions on 16-17 April sent a column 500-700 m high. Seismicity was characterized by numerous B-type earthquakes in March (~50/month), and by volcanic tremors during April (~ 200/month).

Information Contacts: Sakurajima Volcanological Observatory (SVO), Disaster Prevention Research Institute, Kyoto University, Sakurajima-cho, Kagoshima 89114, Japan (Email: ishihara@svo.dpri.kyoto-u.ac.jp); Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan.

02/2001 (BGVN 26:02) Two subsidiary craters discovered; elevated activity in December 2000

An observer on Suwanose-jima reported seeing "smoke" rise from NE of the summit crater at about 1700 on 19 December 2000. The following day, Kazuhiro Ishihara from Sakura-jima Volcano Research Center (SVRC, formerly Sakura-jima Volcano Observatory, SVO) of Kyoto University inspected the crater area during a helicopter flyover. He observed an ash-laden, high-temperature gas emission from the main active crater, On-take, and from two newly formed craters on the outer NE slope of the main crater (figures 2 and 3).

Figure 2. Topographic map of Suwanose-jima illustrating the main active crater (1), On-take, and the newly discovered craters (2, 3). Thick textured lines are crater rims. Contour interval is 100 m. After a map by SVRC.
Figure 3. Photo of the NE slope of Suwanose-jima showing the main active crater (1), On-take, and two subsidiary craters (2, 3). Courtesy of SVRC.

Subsequent observations on 24 December by Masato Iguchi and Daisuke Miki, both of SVRC, revealed more about the nature of the craters' activities. Craters 2 and 3 were ~40 m and ~200 m away from the main crater rim, respectively. Crater 2 had a diameter of ~25 m, and crater 3 had a diameter of ~10 m. The craters were thermally surveyed from a helicopter. On-take (crater 1) had a temperature of ~450°C, and emitted light-colored vapor. Crater 2 released an ash-laden plume and had a temperature of ~100°C. Crater 3, which had a temperature of ~270°C, ejected gas and a small amount of ash.

Seismicity recorded by SVRC showed that ~10 deep volcanic (A-type) earthquakes occurred monthly, an increase since fall 1999. Shallow volcanic (B-type) earthquakes had also increased since early 2000 with the occurrence of ~50-300 events monthly. Researchers using GPS techniques discovered that deformation had increased the distance between Suwanose-jima and Nakano-shima, a neighboring island, by 1 cm. SVRC indicated that activity was elevated, but that it did not imply an immediate large-scale eruption.

Information Contacts: Disaster Prevention Research Institute, Kyoto University (URL: http://www.dpri. kyoto-u.ac.jp/); Setsuya Nakada and Hidefumi Watanabe, Volcano Research Center, Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan (URL: http://hakone.eri.u-tokyo. ac.jp/vrc/VRC.html, Email: nakada@eri.u-tokyo.ac.jp, kaneko@eri.u-tokyo.ac.jp).

07/2001 (BGVN 26:07) Explosive eruptions in May and July

Several eruptions occurred at Suwanose-jima in May-July 2001. Beginning on the morning of 9 May 2001 volcanic activity increased at Suwanose-jima when a tremor event commenced (figure 4). The tremor increased at 1100 and became more violent at 2100.

Figure 4. Daily eruptions, tremor events, and B and A earthquakes registered at Suwanose-jima up to 11 May. Here, an eruption is defined as a volcanic earthquake, associated with an acoustic signal of more than 1 Pa. Courtesy of the Japanese Meteorological Agency.

On 11 May an eruption produced ash clouds that rose to 1.8-7.6 km altitude. A seismo-acoustical record of an eruption signal on 10 May is shown on figure 5. Abundant ash fell on 11 May ~ 4 km NNW of the active On-take (Otake) crater (at Toshima village).

Figure 5. Seismo-acoustical record of an eruption signal received at Suwanose-jima on 10 May. The bottom panel shows the requisite acoustic signal that was recorded by a microphone. Courtesy of the Japanese Meteorological Agency.

Vigorous eruptions on the evening of 12 May and the morning of 13 May deposited up to 3 cm of ash in the village (figure 6). At 0900 on 14 May the eruption seemed to have stopped.

Figure 6. Photo taken from a helicopter of the beginning of the 12 May eruption at Suwanose-jima. Courtesy of the Japanese Meteorological Agency.

The Sakurajima Volcano Observatory also reported that plumes associated with volcanic tremor events have been observed at Suwanose-jima since the new crater was formed during the December 2000 eruption.

Volcanic tremor was also detected near Suwanose-jima's On-take (Otake) crater beginning at 2200 on 25 July and lasting until at least 26 July. JMA reported that an eruption on 26 July at 1430 produced a volcanic plume that rose to 1.3 km above the crater and drifted to the S. That day seismometers ~2 km SW of the crater recorded explosions at 0501, 0558, 0935, and 1055. Ash fell on Toshima the morning of 26 July.

Information Contacts: Japanese Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100 Japan; Tokyo Volcanic Ash Advisory Center, Tokyo, Japan (URL: http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html), Email: vaac@eqvol.kishou.go.jp, ssaito@met.kishou.go.jp); Disaster Prevention Research Institute, Kyoto University, Japan (URL: http://www.dpri. kyoto-u.ac.jp/); Setsuya Nakada and Hidefumi Watanabe, Volcano Research Center, Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan (URL: http://hakone.eri.u-tokyo. ac.jp/vrc/VRC.html, Email: nakada@eri.u-tokyo.ac.jp, kaneko@eri.u-tokyo.ac.jp).

07/2002 (BGVN 27:07) Volcanic tremor, plumes, and ash eruptions during October 2001-August 2002

The Japanese Meteorological Agency (JMA) reported that, following the latest eruptive activity that had ended on 30 July, an eruption began around 1400 on 11 October 2001 at Otake Crater. Volcanic tremor had started around 1200 on 11 October and continued through 15 October. Up to 11 explosions occurred. An acoustic microphone installed on the island recorded four shock waves associated with larger explosions.

On 18 June 2002 during 1130-1300 a plume was observed (figure 7), and on the morning of 19 August 2002, JMA issued a volcanic advisory for Suwanose-jima. Volcanic tremor events associated with continuous acoustic signals (the largest so far in 2002) occurred for 20- to 30-minute periods around 0000 and 0630, and also during 0940-0950, 1410-1500, 1810-1815, and 1920-1930. Small tremor events also occurred. Witnesses in Toshima village heard continuous rumblings and explosion sounds every 2-3 seconds. The summit was covered with clouds and abundant ash drifted SW and SE. The summit crater emitted steam to an unknown height. A large plume was seen on satellite imagery on 19 August (figure 8). Eruption clouds were visible on 10, 16, and 20 August 2002 (figure 9).

Figure 7. Satellite image of the plume from Suwanose-Jima volcano observed at 1132 (local time) on 18 June 2002. The plume was visible from 1130-1300. Courtesy Charles Holliday, AFWA.
Figure 8. Satellite view showing plume emitted from Suwanose-jima on 19 August 2002 at 1808 (local time). Courtesy Charles Holliday, AFWA.
Figure 9. Eruption clouds emitted from Suwanose-jima at 1640 on 10 August 2002. The clouds were observed through live camera images provided by the Satellite Image Network Group (SiNG). Courtesy N. Uchida, JMA.

On 21 and 22 August JMA reported that eruptive activity continued but at a lower level. On 20 August, volcanic tremor events occurred during 0115-0120 and 0625-0655. Witnesses in Toshima village reported that the rumbling noises became weaker, though they were sometimes accompanied by large explosion sounds. Ashfall occurred in Naze city on Amami-oshima island (~140 km S) during the afternoon. Faint ashfall was observed ~4 km SSW of the summit on 20 and 21 August.

Observations from the air on 21 August revealed the December 2000 crater (BGVN 26:02) generating an ash cloud to 1.5 km above the crater that was drifting S.

Information Contacts: N. Uchida, Japanese Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (Email:n-uchida@met.kishou.go.jp); Volcano Research Center (VRC), Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan (URL: http://hakone.eri.u-tokyo.ac.jp/); Charles Holliday, Air Force Weather Agency (AFWA), Satellite Applications Branch, Offutt AFB, NE 68113-4039 (Email: charles.holliday@afwa.af.mil); Satellite Image Network Group (SiNG), Faculty of Education, Kagoshima University, Kagoshima 890, Japan.

04/2003 (BGVN 28:04) Ash explosions in September and December 2002, and activity in January 2003

Though the volcano had been relatively quiet since 26 August 2002 (BGVN 27:07), the Japan Meteorological Agency reported that explosive eruptions became frequent on the morning of 12 September 2002. Rumbling was heard intermittently at a location ~4 km SSW of the summit, and light ashfall was observed on 12 September. Explosions occurred at 0816, 1246, 1746, and 1754 on 12 September, and at 0853, 1016, and 1027 on 13 September.

A pilot report contained in the Kagoshima Airport weather observation issued at 1000 on 5 December 2002 noted a plume estimated to be between 900 and 1,200 m altitude. The U.S. Air Force Weather Agency noted that the plume was also seen on DMSP (Defense Meteorological Satellite Program) imagery at 1034 and on NASA Terra MODIS imagery at 1055 on 5 December.

The REAL-Volc Project at the Volcano Research Center, Earthquake Research Institute, University of Tokyo, has detected several thermal anomalies on Suwanose-jima since they started an AVHRR monitoring system in 2001. Anomalies were seen on 11 October 2001, 20 November 2001, 30 December 2001, 20 April 2002, and 12 January 2003.

Information Contacts: Naokuni Uchida, Japan Meteorological Agency (JMA-Fukuoka Center), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (Email: uchida@met.kishou.go.jp); Takayuki Kaneko, Volcano Research Center, Earthquake Research Institute, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan (URL: http://hakone.eri.u-tokyo.ac.jp/vrc/VRC.html, http://vrsserv.eri.u-tokyo.ac.jp/REALVOLC/, Email: nakada@eri.u-tokyo.ac.jp, kaneko@eri.u-tokyo.ac.jp); Charles Holliday, U.S. Air Force Weather Agency, 106 Peacekeeper Drive, Ste 2NE, Offut AFB, NE 68113-4039, USA (URL: https://afweather.afwa.af.mil/, Email: Charles.Holliday@afwa.af.mil).

03/2004 (BGVN 29:03) Sporadic eruptions in 2003 and in January 2004, one to 2.4 km altitude

Suwanose-jima volcano was last reported in BGVN 28:04, when activity was noted in September and December 2002, with thermal anomalies continuing into January 2003. HIGP MODIS thermal imagery revealed only one alert in the year to 13 April 2004, that being on 4 July 2003. NASA Terra and Defense Meteorological Satellite Program imagery dated 7-8 November 2003 showed an ash plume rising from Suwanose-jima to an estimated height of 2,400 m (figure 10) on those days.

Figure 10. Ash plume from Suwanose-jima on 8 November 2003 imaged by the MODIS instrument on the NASA AQUA satellite. Courtesy Defense Meteorological Satellite Program (DMSP) and Charles Holliday.

According to Tokyo VAAC reports, using information from the Japanese Meteorological Agency, explosions also took place at Suwanose-jima on 15 December 2003 at 1946, and 21 December at 1828, each of which produced plumes to an unknown height. The VAAC reported several small emissions on 27 and 28 December, again rising to unknown heights and an eruption on 28 December at 0820 rising to ~ 1.5 km altitude and extending E. On 2, 4 and 21-22 January 2004 small explosions produced ash plumes to unknown heights.

Information Contacts: Japan Meteorological Agency (JMA), Volcanological Division 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (URL: http://www.kishou.go.jp/english/), HIGP MODIS Thermal Alert System, Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa (http://modis.higp.hawaii.edu/); Charles Holliday, Air Force Weather Agency (AFWA), Satellite Applications Branch, Offutt AFB, NE 68113-4039, USA (Email: charles.holliday@afwa.af.mil).

07/2005 (BGVN 30:07) Eruptions during April 2004-July 2005 send plumes to varying heights

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      Event                    Plume
                                                              Altitude (km)    Direction

    28 Apr 2004             --       ash emission                  3              SE
    01 May 2004            0906      explosion                     --             --
    07 Jun 2004             --       gas plume                     2               E
    08 Jun 2004             --       gas and ash                   2               E
    09 Jun 2004            1003      ash plume                     1.8             E
    09 Jun 2004            1300      ash plume                     --             --
    30 Jun-05 Jul 2004    various    several explosions        max 1.9            --
    30 Nov 2004            1607      eruption                      1.2            --
    20 Dec 2004             --       eruption                      1.8            SE
    21 Dec 2004             --       eruption                      --             SE
    22 Dec 2004             --       ash plume                     --             --
    24 Dec 2004             --       ash plume                     --             --
    25 Dec 2004             --       ash plume                     --             --
    27 Dec 2004             --       ash plume                     --             --
    29 Dec 2004             --       ash plume                     1.2            --
    01 Jan 2005             --       eruption                      --             --
    04 Jan 2005             --       eruption                      --             --
    06 Mar 2005             --       ash emission                  1.5            --
    08 Mar 2005             --       ash emission                  1.2            --
    09 Mar 2005             --       ash plume                     1.8            --
    26 Apr 2005             --       eruption                      1.2             E
    26 May-31 May 2005    various    several ash explosions    max 2.1            --
    01 Jun-06 Jun 2005    various    several ash explosions        1.8            --
    06 Jul 2005           various    several ash explosions        --             --
    27 Jul 2005             --       eruption with ash             0.8            --
    28 Jul 2005             --       ash plume                     2.4            --

Information Contacts: Tokyo Volcanic Ash Advisory Center, 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).

11/2007 (BGVN 32:11) Eruptions of July 2005-December 2007 send plumes to varying heights

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.

    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 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.

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/).

02/2008 (BGVN 33:02) Small (~1 km) plumes noted during late 2007-early 2008

Our last Bulletin (BGVN 3211) covered eruptive activity during July 2005 to December 2007. This issue covers eruptions recorded by the Tokyo Volcanic Ash Advisory Center (VAAC) from December 2007 to March 2008. Kinoshita and others (2003) noted that Sakura-jima "has been the most eruptive in Japan, with the eruption columns a few kilometers above the crater occasionally."

Table 5 summarizes information gathered by the Tokyo VAAC from observers between 9 December 2007 and 21 March 2008. In all cases the VAAC could not detect plumes using satellite data. An overview of satellite and image monitoring of Suwanose-jima appears in an article by Kinoshita and others (2003).

Table 5. A summary of Tokyo VAAC reports on ash plumes from Suwanose-jima during 9 December 2007 to 21 March 2008. Cases with only dashes in the data fields were when observers detected an explosion but they were unable to say more about a resulting plume. In many of the examples given, there were multiple Volcanic Ash Advisories issued, but no new data came to light. Courtesy of the Tokyo VAAC.

    Date           Time (UTC)    Ash cloud altitude    Direction

    09 Dec 2007       2340            1.5 km              W
    10 Dec 2007       0734            1.8 km              W
    14 Dec 2007       0914            --                  --
    15 Dec 2007       0016            1.8 km              E
    16 Dec 2007       0353            1.5 km              E
    16 Dec 2007       2310            1.5 km              E
    08 Feb 2008       0248            1.8 km              E
    13 Feb 2008       0208            --                  --
    21 Mar 2008       1622            --                  --

Reference. Kinoshita, K., Kanagaki, C., Minaka, A., Tsuchida, S., Matsui, T., Tupper, A., Yakiwara, H., and Iino, N., 2003, Ground and Satellite Monitoring of Volcanic Aerosols in Visible and Infrared Bands: The CEReS International Symposium on Remote Sensing - Monitoring of Environmental Change in Asia, Chiba, Japan, 16-17 December 2003, 10 p.

Information Contacts: Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://www.jma.go.jp/jma/jma-eng/jma-center/vaac/vaac%20operation.htm).

09/2008 (BGVN 33:09) Eruption continues from 2007 into 2008

Historically, Suwanose-jima (figure 12) has been one of Japan's most frequently active volcanoes. Our last report on Suwanose-jima, (BGVN 33:02) listed ash plumes between 9 December 2007 and 21 March 2008. This report continues the list through 26 October 2008.

Figure 12. Simplified map of the geology of Suwanose-jima. The active crater, O-take (Oc), appears at the southern end of the small, sparsely populated island. Courtesy of Taketo Shimano.

According to a 2008 International Civil Aviation Organization (ICAO) report, the Tokyo VAAC issued 70 volcanic ash advisories for Suwanose-jima during the 17-month period of January 2007-May 2008. This included seven from January through May 2008 (ICAO, 2008). Table 6 summarizes reports of explosive events and plumes for January-October 2008.

Table 6. A summary of Tokyo VAAC reports on explosive events and resulting ash plumes from Suwanose-jima from April through October 2008 (continued from table in BGVN 33:02). For some events, observers detected an explosion but were unable to observe a resulting plume. Courtesy of Tokyo VAAC, based on information from the Japanese Meteorological Agency (JMA) or pilot reports.

    Date (UTC)            Plume Altitude    Drift direction

    16 Apr 2008           not observed      not observed
    16 Jun 2008           not observed      not observed
    29 Jul 2008           0.6 km            S
    07 Aug 2008           1.2 km            not observed
    24-26 Aug 2008        1.8-2.4 km        not observed
    04-06 Sep 2008        1.5-1.8 km        E (5 September)
    24-29 Sep 2008        1.5-3 km          NE, E, and SW
    01-02 Oct 2008        not observed      not observed
    07-10 Oct 2008        2.1 km            not observed
    16, 18-20 Oct 2008    1.2-2.5 km        W
    21, 23, and
      25-26 Oct 2008      1.5-3.0 km        W and E

MODIS/MODVOLC thermal alerts were measured by satellite-borne radiospectroradiometer during 2008 through 6 November (table 7). The island is often covered by clouds, preventing consistent detections.

Table 7. Thermal anomalies measured by MODIS satellite analyzed by the MODVOLC algorithm for Suwanose-jima volcano in 2008 through 6 November. Courtesy of Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System.

    Date           Time (UTC)    Pixels    Satellite

    30 Jul 2008      1710          1       Aqua
    31 Jul 2008      1335          1       Terra
    22 Sep 2008      1350          1       Terra

NASA satellite observation of 19 October 2008. According to the NASA MODIS Rapid Response team and the NASA Earth Observatory, the volcano released a continuous plume of ash and steam in late October 2008. They noted that a Moderate Resolution Imaging Spectroradiometer (MODIS) captured an image of an ash plume on 19 October 2008. In this image, the plume formed a rippling pattern as it blew WSW. The plume differed from the nearby clouds in both its slightly darker color and more diffuse shape. Near the summit, the plume appeared beige.

References. International Civil Aviation Organization (ICAO), 2008, Fourth Meeting of the International Airways Volcano Watch Operations Group (IAVWOPSG), Paris, France, 15-19 September 2008: Working Paper 34, VAAC Tokyo Management Report, 6 p. (URL: http://www.icao.int/anb/iavwopsg/meetings/iavwopsg4/wp).

Information Contacts: Taketo Shimano, College of Environment and Disaster Research, Fuji-Tokoha University, 325 Obuchi, Fuji-shi, Sizuoka 417-0801, Japan (URL: http://www.eri.u-tokyo.ac.jp/shimano/); International Airway Volcanic Watch Operations Group of the International Civil Aviation Organization (URL: http://www.icao.int/anb/iavwopsg); Tokyo Volcanic Ash Advisory Center (VAAC) (URL: http://ds.data.jma.go.jp/svd/vaac/data/; http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html); NASA MODIS Rapid Response team, NASA Goddard Space Flight Center NASA; NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/NaturalHazards); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/).

07/2009 (BGVN 34:07) Explosive eruptions continue through 6 July 2009

This small uninhabited island, one of Japan's most active volcanoes, lies ~ 175 km SSW of Kyushu Island. Previous reports on Suwanose-jima (BGVN 30:07, 32:11, 33:02, and 33:09) listed ash plumes between 28 April 2004 and 26 October 2008. This report continues the compilation through 6 July 2009 (table 8). Ash plumes were consistent and minor, below ~ 2.5 km altitude.

Table 8. A summary of Tokyo Volcanic Ash Advisory Center (VAAC) reports on explosive events and ash plumes from Suwanose-jima, 29 October 2008 to 6 July 2009. For some events, observers detected an explosion but were unable to observe a plume (NR indicates not reported). Courtesy of Tokyo VAAC, based on information from the Japanese Meteorological Agency (JMA), pilot reports, and satellite imagery.

    Date (UTC)               Plume altitude                Drift direction

    29-30 Oct 2008           1.5-1.8 km                    E
    31 Oct-01 Nov 2008       Explosions, plume data NR
    03 Nov 2008              1.5-1.8 km                    E
    05 Nov 2008              1.5 km                        NE
    07 Nov-08 Nov 2008       1.2-1.8 km                    E
    12 Nov-16 Nov 2008       Explosions, plume data NR
    13 Nov-15 Nov 2008       1.5-2.1 km                    --
    21 Nov 2008              1.5 km                        E
    25 Nov 2008              Explosions, plume data NR
    10 Dec-12 Dec 2008       0.9-1.8 km                    E
    14 Dec-17 Dec 2008       0.9-1.8 km                    E
    19 Dec-20 Dec 2008       1.5 km                        E (17, 19 Dec)
    26 Dec-28 Dec 2008       1.5-1.8 km                    --
    30 Dec 2008              Explosions, plume data NR
    03 Jan 2009              1.2 km                        E
    09 Jan 2009              Explosion, plume data NR
    21 Jan 2009              Explosion, plume data NR
    18 Feb-21 Feb 2009       Explosions, plume data NR (colored plume on 18 Feb rose 400 m)
    26 Feb-02 Mar 2009       1.2-1.5 km                    E (1 Mar)
    03 Mar 2009              Explosion, plume data NR
    06 Mar 2009              Explosions, plume data NR
    15 Mar-16 Mar 2009       1.5 km                        E (15 Mar)
    28, 30 Mar 2009          Explosion, plume data NR
    06, 8, 10 Apr 2009       Explosions, plume data NR
    21 Apr 2009              Explosion, plume data NR
    22 Apr-23 Apr 2009       1.2-1.5 km                    E, S
    27 Apr 2009              Explosion, plume data NR
    28 Apr-01 May 2009       1.5-1.8 km                    E, W
    07-09, 12-13 May 2009    Explosions, plume data NR
    17 May 2009              2.1 km                        --
    25 May 2009              1.5 km                        --
    16 Jun 2009              Explosion, plume data NR
    06 Jul 2009              Explosion, plume data NR

Yukio Hayakawa passed along quantitative data on the explosive eruption on 18 February 2009. The maximum amplitude of ground velocity computed from the analog data was expressed in units of 10-5 m/s (in Japan this unit is expressed as mkine). The values on the 18th were 5.38 x 10-5 m/s; and the airwave was 11 Pa. Hayakawa also indicated that the two explosive eruptions on 20 February had maximum amplitudes of 4.31 x 10-5 m/s and 5.76 x 10-5 m/s, respectively. The airwaves recorded were 20 and 18 Pa, respectively at microphones.

A visible-wavelength image from MODIS captured a small Suwanose-jima plume on 5 July 2009 (figure 13). As of mid-2009, no thermal alerts had been recorded by MODVOLC since 22 September 2008. The island is often covered by clouds, thwarting detection.

Figure 13. Image of Suwanose-jima taken on 5 July 2009 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. A beige-colored plume fans out and remains conspicuous for ~ 18 km to the NE blowing toward the island of Yaku-shima. Courtesy of NASA Earth Observatory and the US Air Force Weather Agency.

Information Contacts: Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/); Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html); U.S. Air Force Weather Agency (AFWA)/XOGM, Offutt Air Force Base, NE 68113, USA; Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/); Yukio Hayakawa, Gunma University, Faculty of Education, Aramaki 4-2, Maebashi 371-8510, Japan.

07/2011 (BGVN 36:07) Many small explosions up to 2 km altitude during mid-2009 to mid-2011

In a previous report (BGVN 34:07) we discussed ash plume data from the Tokyo Volcanic Ash Advisory Center (VAAC) and reports from the Japan Meteorological Agency (JMA) that covered explosive activity based on infrasound measurements and seismicity during October 2008 to July 2009. Many explosions were heard and felt but cloud cover obscured direct observations. From 6 July 2009 to 14 July 2011 the Tokyo VAAC reported 234 explosions; 62 of which produced a measurable ash plume (table 9) from the summit crater, On-take (also called Otake).

Table 9. A summary of Tokyo Volcanic Ash Advisory Center (VAAC) reports on measured ash plumes from Suwanose-jima, 15 July 2009 to 14 July 2011. Courtesy of Tokyo VAAC, based on information from the JMA, pilot reports, and satellite imagery.

    Date              Altitude (km)      Drift

    15-17 Jul 2009      1.5-2.1          NE, W
    16-17 Aug 2009          1.8            E
    28-29 Aug 2009      1.5-2.4            W
    17-18 Sep 2009          1.5            S
    01 Oct 2009             1.5            W
    10 Oct 2009             1.5            —
    04-05 Nov 2009      1.2-1.8        SW, W, NE
    26 Nov 2009             3.0            E
    14 Dec 2009         1.2-1.5            E
    22 Dec 2009             1.5            —
    02 Jan 2010             1.8            —
    04-05 Jan 2010      1.5-1.8          NE, E
    09 Jan 2010             1.8            E
    26-27 Jan 2010      1.2-1.5          SE, W
    29 Jan 2010             1.8            —
    17 Feb 2010         1.2-1.5          E, SE
    19 Feb 2010             1.5            SE
    21 Feb 2010             1.8            —
    15-16 May 2010      1.5-1.8            NW
    23 Jul 2010             2.4            NW
    26 Jul 2010             1.5             W
    22 Sep 2010         1.5-2.1            SE
    25 Sep 2010             1.5             E
    05 Oct 2010             1.5             E
    17 Oct 2010             1.5            SE
    10-12 Nov 2010      1.5-2.1         SE, N, SW
    18 Nov 2010             1.8             —
    21 Nov 2010             2.1            NE
    29 Nov 2010         1.2-1.5             —
    04 Dec 2010             1.2            SE
    13 Jan 2011             1.2            SE
    22 Jan 2011             1.5             S
    05 Feb 2011             0.6            SW
    12 Apr 2011             1.8             —
    14 Jul 2011             3.7             —

JMA stated that this volcano has erupted every year since 1956. The activity alert status for Suwanose-jima was Level 2 (on a 1 to 5 scale where 5 is the highest) from December 2007 to July 2011; this status indicates that the crater is too dangerous to visit.

Activity during late 2009. The Tokyo VAAC reported frequent plumes from mid-August through December 2009. The tallest plumes, above 1.5 km altitude, occurred on 16-17 and 29 August, and 5 and 26 November (table 9). According to JMA, a visitor during 29-30 December 2009 saw Strombolian eruptions.

Activity during 2010. Ash plumes up to ~ 2.4 km altitude were reported by the Tokyo VAAC on many days throughout the year (table 9).

Based on the seismic record, JMA was able to infer when explosions occurred within the crater. The number of these explosions decreased from 64 in January to 0 in June; from July to September there were less than 20 monthly explosions, but activity appeared to peak in November when 94 explosions were recorded.

Aerial observations were made in collaboration with the Japan Maritime Self Defense Force (JMSDF) on 14 December (figure 14). The flight confirmed high temperature areas at both the summit crater's center and at the lower, outer rim. Thes results were congruent with those obtained earlier, in December 2009, and JMA concluded that similar conditions prevailed in the crater during this interval.

Figure 14. Thermal imaging of Suwanose-jima's summit crater, On-take, taken on 14 December 2010. On the false-color scale (calibrated at right), the highest temperatures are white, the lowest temperatures are blue, showing values in Celsius. The maximum temperature from photo B is 442.5°C; maximum temperature from photo D is 106.1°C. Courtesy of JMA; photos by the Japan Maritime Self Defense Force (JMSDF), Kanoya Air Base.

Activity during 2011. Ash plumes were reported by the Tokyo VAAC for January, February, April, and July; the tallest occurred on July 14 and reached ~ 3.6 km altitude (table 9). From January to July 2011, volcanic earthquakes and tremor remained relatively high (figure 15).

Figure 15. Geophysical data recorded for Suwanose-jima from 2003 to July 2011. The uppermost plot indicates eruptions (red arrows, at top) and the daily maximum plume height in meters (histogram). High-frequency (A-type) earthquakes are separated from low-frequency (B-type) earthquakes. JMA also reported monthly tremor durations (not shown here). Courtesy of JMA.

A 2.9-magnitude earthquake centered below Suwanose-jima occurred on 3 February 2011 at 2206. That month, local inhabitants reportedly felt 17 earthquakes. No surface change was observed before or after the earthquakes. Surveillance in February 2011 included visual observations by the Coast Guard.

Immediately after the 11 March 2011 Tohoku Earthquake (M 9.0, located offshore of Honshu, Japan) instruments at Suwanose-jima recorded increases in high-frequency (A-type) earthquakes. A-type earthquakes are generally considered to have shallow focal depths; B-type earthquakes, deeper focal depths.

Ash explosions seemingly rarely occurred through March 2011, but reports from Toshimamura village stated that observers there had seen ballistics thrown from the summit crater. Due to prolonged poor weather, surveillance cameras did not record this activity. JMA reported that plume heights for April, May, and June 2011 remained at background levels, with maximum heights of 0.4?1.0 km. Intermittent incandescence was recorded with surveillance cameras when clear weather allowed observations at night from March through June.

Information Contacts: Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/); Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html); Yukio Hayakawa, Gunma University, Faculty of Education, Aramaki 4-2, Maebashi 371-8510, Japan.

08/2012 (BGVN 37:08) 2011-2012 eruptions with plumes rising up to 1 km above crater rim

Our last report covered beharior at Suwanose-jima through July 2011 (BGVN 36:07). This report, compiling translated material from the Japan Meteorological Agency (JMA), covers ongoing activity through June 2012, with minor magnitude venting at Otake crater and the tallest plume rising to 1 km over the crater rim. Throughout the reporting period, the volcano’s crater produced weak glow at night that was imaged by a high-sensitivity camera. The Alert Level remained at Level 2 (on a scale from 1-5, access to the crater area prohibited due to threat of eruption). As summarized in the text, numbers of A- and B-type events were in the ranges of 11-24 and 62-205, respectively. There were multiple cases of ashfall at Toshima village (“Toshimamura”), 4 km SSW from the summit crater.

The table below summarizes some other information reported by JMA, including a tally of small eruption heights. Tremor duration extended to over 50 hours during several months and to 132 hours in June 2012.

Monthly coverage. Volcanic earthquakes and tremor continued during July and August 2011 (table 10). In August, seismic activity decreased; A- and B-type events occurred 24 and 62 times, respectively. A-type earthquakes are generally considered to have shallow focal depths; B-type earthquakes, deeper focal depths.

Table 10. A compilation of data on Suwanose-jima during July 2011 through June 2012. ‘-’ indicates data not reported. Data courtesy of JMA.

                No. of       Tremor duration    Maximum plumeMonth & year    explosive    (hours:minutes)    height (m above    Other activity                eruptions                       the crater rim)Jul 2011           0               -                 400           Prolonged activityAug 2011           0             15:23               300           Prolonged activitySep 2011           2             64:00             300-1,300       Small eruptions on                                                                     8,9,11, and 12 SepOct 2011           0             18:51              1,000          Small eruption on 1 OctNov 2011           0             28:30               600           Small eruption on 15 NovDec 2011           0             None                400           Jan 2012           1             69:24               300Feb 2012           1             00:58               400Mar 2012           1             00:17              ~200Apr 2012           0              9:26               300May 2012           0             40:11               600           Very small eruptions on                                                                      25,26, and 28-30 MayJun 2012           0            132:24               300           Very small eruptions on                                                                     11 and 13-14 Jun

Explosive eruptions from Otake crater occurred on 9 and 12 September 2011. A temporal increase in seismicity, including intermittent tremor, was observed during 9-14 September, later dropping to background level. Ash fell at Toshimamura on 7, 9, 12, 15, and 18 September.

Small-scale eruptions were observed in October and November 2011. Ashfall was reported at Toshimamura on 15 November.

Aerial observations were conducted in cooperation with the Japan Maritime Self Defense Force (JMSDF) on 19 December 2011. They revealed a high temperature area at the center of Otake crater.

GPS measurements showed no remarkable crustal change between January and June 2012. GPS data from Tongama ceased starting in mid-May due to a technical failure.

No explosive eruptions occurred in April 2012. Instruments detected 21 A-type events and 85 B-type events.

During May, there were 11 A-type events and 205 B-type events. Noteable volcanic tremor occurred on 5 and 25-26 May. Toshima village registered ashfall on 25 and 28-30 May.

Toshima village again reported ashfall on 11 and 13-14 June 2012. During June instruments detected 21 A-type events and 116 B-type events. Volcanic tremor was registered during 2?22 June 2012 (table 10).

Information Contacts: Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html).

04/2013 (BGVN 38:04) Near continuous tremor between July 2012 and March 2013

This report discusses Suwanose-jima (figure 16) during July 2012 through April 2013, an interval with generally abundant tremor, low numbers of earthquakes, weak plumes (less than 0.7 km above the crater rim), and occasional intermittent eruptions. Our previous report on Suwanose-jima discussed seismicity through June 2012 that included volcanic earthquakes and tremor, minor explosions, and plumes which occasionally deposited ash on nearby Toshima village as late as June 2012 (BGVN 37:08).

Figure 16. Satellite image showing the location of Suwanose-jima. Courtesy of Google Earth.

Recent monthly reports of volcanic activity from the Japan Meteorological Agency (JMA) translated into English resumed in October 2010. Since June 2012, English-translated JMA reports on Suwanose-jima were available online every month through March 2013

According to JMA, seismic activity at Suwanose-jima remained at low levels between July 2012 and March 2013. Although explosive eruptions have occurred repeatedly in the past, no such eruption occurred during the reporting period. However, JMA reported infrequent tiny eruptions. Volcanic tremor occurred almost continually between 28 September 2012 and March 2013. A high-sensitivity camera often detected a weak night glow during every month. No unusual ground deformation was seen in GPS observation data. Table 11 summarizes tremor activity and other information reported by JMA.

Table 11. A compilation of data on Suwanose-jima between July 2012 and March 2013. '-' indicates data not reported. A-type earthquakes are generally considered to have shallow focal depths; B-type earthquakes, deeper focal depths. An asterisk "*" in the earthquake column indicates that the number of events reported for a specific month conflicts with the number reported for that same month in the sequential monthly JMA report. Data courtesy of JMA.

    Month       Earthquakes          Tremor duration    Max plume height                                     (hours:minutes)    (m above crater rim)                Other activity    Jul 2012    29 A-type events,    38:5               400                                     123 B-type events        Eruption.    Aug 2012    17 A-type events,    0:0 (or 0:1)*      300                39 B-type events                               (or 60 events)*             No eruption.  Plume on 19 Aug only.    Sep 2012    37 A-type events,    0:1 (or 67:52)*    300-400                86 B-type events                   (or 74 events)*           No eruption.  White plumes.  11 Sep aerial observation spotted white        plume above Shindake crater.    Oct 2012    22 A-type events,    705:19             700                      78 B-type events.        Tiny intermittent eruptions at Otake crater.  According to Tokyo VAAC,        an ash plume on 3 Oct drifted SW at altitude of 3 km (i.e. 1.5 km        higher than the JMA reported).  Ashfall on Toshima village, 4 km SSW        of Otake, on 2 and 5 Oct.    Nov 2012    --                   720:0              500-600                 Tiny intermittent eruptions.  Tiny amount of ashfall on Toshima village           on 25 Nov.    Dec 2012    --                   622:23             500               Tiny intermittent eruptions on 26th, red hot mass seen.     Jan 2013    --                   744:0              500            White plumes    Feb 2013    --                   672:0              500               M 3.6 earthquake on 19 Feb with aftershocks.  Tiny intermittent eruption        on 3 Feb.  Tiny amount of ashfall on Toshima village on 3 Feb.     Mar 2013    --                   --                  500            Tremor data unavailable.    Apr 2013    --                   --                  700                                                                                Small eruption on 13 April. Tremor data unavailable.

 

On 8 November 2012, a field survey at Bunka crater revealed no remarkable change in the crater's shape. Infrared images showed no significant change in the crater's temperature distribution. On 26 December 2012, an aerial observation revealed a red-hot lava mass inside Otake crater. This phenomenon has occasionally been observed in past observations.

On 19 February 2013, a M 3.6 earthquake occurred (apparently at Suwanose-jima). The earthquake's maximum seismic intensity on JMA's scale was 3 (felt indoors by most or all people, objects rattle and fall off tables, houses shake strongly and may receive slight damage). In addition, a swarm of ten earthquakes (aftershocks?) with seismic intensities of 1 or greater on JMA's scale were recorded. These earthquakes caused no significant changes in surface phenomena or tiltmeter data. Seismicity remained at low levels, with hypocenters located just beneath the Otake crater.

Information Contacts: Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html ); Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/ ).

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 persons live on the island.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2004 Oct 23 2014 Sep 9 (continuing) Confirmed 2 Historical Observations O-take
2000 Dec 19 2004 Jul 5 (?) Confirmed 3 Historical Observations O-take (Upper NE flank)
2000 Feb 24 ± 4 days 2000 Feb 24 ± 4 days Confirmed 2 Historical Observations O-take
1999 Jun 15 ± 5 days 1999 Jun 30 ± 4 days Confirmed 1 Historical Observations O-take
1999 Jan 5 ± 5 days 1999 Feb 24 ± 4 days Confirmed 1 Historical Observations O-take
1996 Dec 26 1997 Apr 17 Confirmed 1 Historical Observations O-take
1990 Apr 1996 Jul 14 Confirmed 2 Historical Observations O-take
1988 Jan 1989 Dec Confirmed 2 Historical Observations O-take
1985 Sep 1987 Jun Confirmed 2 Historical Observations O-take
1984 Oct 1984 Oct Confirmed 2 Historical Observations O-take
1960 (?) Unknown Confirmed 0 Historical Observations Submarine E flank (Suwanose-jima Oki)
1956 Nov 1984 May Confirmed 2 Historical Observations O-take
1954 (?) Unknown Confirmed 0 Historical Observations Submarine E flank (Suwanose-jima Oki)
1949 Oct 1954 Confirmed 2 Historical Observations O-take
1940 Nov 29 Unknown Confirmed 2 Historical Observations O-take
1938 Mar 11 1938 Mar 11 Confirmed 2 Historical Observations O-take
[ 1934 Jan 11 ] [ Unknown ] Uncertain 2   O-take
1925 May 13 Unknown Confirmed 2 Historical Observations O-take
1921 Dec 8 1922 Jan 26 Confirmed 2 Historical Observations O-take
[ 1915 Jul ] [ 1915 Sep ] Uncertain 2   O-take
[ 1914 Mar 21 ] [ Unknown ] Uncertain     O-take
1889 Oct 2 1889 Oct 13 Confirmed 4 Historical Observations O-take
1885 Jan 1885 May Confirmed 2 Historical Observations O-take
1884 Unknown Confirmed 1 Historical Observations Northeastern summit crater (O-take)
1877 Unknown Confirmed 4 Historical Observations
1813 1814 Confirmed 4 Historical Observations SW ridge fissure and O-take
1600 (?) Unknown Confirmed 4 Tephrochronology

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.


Synonyms

Suwanose-zima | Moe-shima | Suwanose-jima

Cones

Feature Name Feature Type Elevation Latitude Longitude
Makko-dai Stratovolcano
Nabedao
    Negami-dake
Stratovolcano 409 m
Otake
    Ontake
Stratovolcano 796 m 29° 38' 18" N 129° 42' 50" E
Susaki Cone
Suwanosejima Oki Submarine cone 29° 38' 30" N 129° 50' 0" E
Tondachi
    Tondati
Cone 536 m

Craters

Feature Name Feature Type Elevation Latitude Longitude
Sakuchi Caldera
Tongama Crater
A steam plume rises above On-take, the summit crater of Suwanose-jima volcano. The 8-km-long, spindle-shaped island of Suwanose-jima consists of a stratovolcano with two historically active summit craters. The dipping escarpment at the top of the photo is the NW wall of a large breached crater that extends to the sea on the east flank. The horseshoe-shaped crater was formed by edifice collapse. Suwanose-jima, one of Japan's most frequently active volcanoes, has been in a state of intermittent strombolian activity since 1949.

Photo by Yukio Hayakawa, 1998 (Gunma University).
An ash plume rising above the summit crater of Suwanose-jima is photographed from a helicopter on May 12, 2001. Vigorous eruptions on the evening of May 12 and the morning of the 13th deposited up to 3 cm of ash in Toshima village, about 4 km NNW of the crater. After a quiet period of about 10 months, eruptive activity had resumed on December 19, 2000 and continued intermittently until July 2004.

Photo courtesy of Japan Meteorological Agency, 2001.
This photo of the NE slope of Suwanose-jima taken on December 20, 2000, the day after the onset of an explosive eruption, shows the main active crater, On-take (labeled 1), and two subsidiary craters (also labeled). Explosive activity continued intermittently until July 2004.

Photo by Kazuhiro Ishihara, 2000 (Sakura-jima Volcano Research Center).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Japan Meteorological Agency, 1996. National Catalogue of the Active Volcanoes in Japan (second edition). Tokyo: Japan Meteorological Agency, 502 p (in Japanese).

Japan Meteorological Agency, 2013. National Catalogue of the Active Volcanoes in Japan (fourth edition, English version). Japan Meteorological Agency.

Kuno H, 1962. Japan, Taiwan and Marianas. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 11: 1-332.

Nakano S, Yamamoto T, Iwaya T, Itoh J, Takada A, 2001-. Quaternary Volcanoes of Japan. Geol Surv Japan, AIST, http://www.aist.go.jp/RIODB/strata/VOL_JP/.

Shimano T, Koyaguchi T, 2001. Eruption styles and degassing process of ascending magma of the 1813 eruption of Suwanose-jima volcano, southwest Japan. Bull Volc Soc Japan (Kazan), 46: 53-70 (in Japanese with English abs).

Volcano Types

Stratovolcano(es)
Pyroclastic cone(s)
Fissure vent(s)

Tectonic Setting

Subduction zone
Oceanic crust (< 15 km)

Rock Types

Major
Andesite / Basaltic Andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
107
107
325
1,966

Affiliated Databases

Large Eruptions of Suwanosejima Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.