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Soputan

Photo of this volcano
  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 1.112°N
  • 124.737°E

  • 1,785 m
    5,856 ft

  • 266030
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 1 April-7 April 2020 Citation IconCite this Report

The Darwin VAAC reported that on 2 April an ash plume from Soputan was seen by a pilot drifting W at an altitude of 4.3 km (14,000 ft) a.s.l.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


Most Recent Bulletin Report: May 2020 (BGVN 45:05) Citation IconCite this Report

Minor ash emissions during 23 March and 2 April 2020

Soputan is a stratovolcano located in the northern arm of Sulawesi Island, Indonesia. Previous eruptive periods were characterized by ash explosions, lava flows, and Strombolian eruptions. The most recent eruption occurred during October-December 2018, which consisted mostly of ash plumes and some summit incandescence (BGVN 44:01). This report updates information for January 2019-April 2020 characterized by two ash plumes and gas-and-steam emissions. The primary source of information come from the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and the Darwin Volcanic Ash Advisory Center (VAAC).

Activity during January 2019-April 2020 was relatively low; three faint thermal anomalies were observed at the summit at Soputan in satellite imagery for a total of three days on 2 and 4 January, and 1 October 2019 (figure 17). The MIROVA (Middle InfraRed Observation of Volcanic Activity) based on analysis of MODIS data detected 12 distal hotspots and six low-power hotspots within 5 km of the summit during August to early October 2019. A single distal thermal hotspot was detected in early March 2020. In March, activity primarily consisted of white to gray gas-and-steam plumes that rose 20-100 m above the crater, according to PVMBG. The Darwin VAAC issued a notice on 23 March 2020 that reported an ash plume rose to 4.3 km altitude; minor ash emissions had been visible in a webcam image the previous day (figure 18). A second notice was issued on 2 April, where an ash plume was observed rising 2.1 km altitude and drifting W.

Figure (see Caption) Figure 17. Sentinel-2 thermal satellite imagery detected a total of three thermal hotspots (bright yellow-orange) at the summit of Soputan on 2 and 4 January and 1 October 2019. Sentinel-2 atmospheric penetration (bands 12, 11, 8A) images courtesy of Sentinel Hub Playground.
Figure (see Caption) Figure 18. Minor ash emissions were seen rising from Soputan on 22 March 2020. Courtesy of MAGMA Indonesia.

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); MAGMA Indonesia, Kementerian Energi dan Sumber Daya Mineral (URL: https://magma.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).

Weekly Reports - Index


2020: March | April
2019: May
2018: September | October | December
2016: January | February | March | April
2015: January | February | March | May | June | July | November | December
2014: April | August | December
2013: April | June
2012: May | August | September | November
2011: June | July | August | September
2008: June | October
2007: June | August | October
2006: December
2005: April | December
2004: October | December
2003: July | August | September


1 April-7 April 2020 Citation IconCite this Report

The Darwin VAAC reported that on 2 April an ash plume from Soputan was seen by a pilot drifting W at an altitude of 4.3 km (14,000 ft) a.s.l.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


18 March-24 March 2020 Citation IconCite this Report

The Darwin VAAC reported that on 23 March an ash plume from Soputan was seen by a pilot rising to an altitude of 4.3 km (14,000 ft) a.s.l.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


22 May-28 May 2019 Citation IconCite this Report

PVMBG reported that during 22-28 May white plumes rose as high as 100 m above Soputan’s summit. On 27 May white-to-gray plumes rose 150 m high. The Alert Level remained at 3 (on a scale of 1-4). The public was advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


12 December-18 December 2018 Citation IconCite this Report

PVMBG reported that seismic activity at Soputan rapidly and significantly increased at 1700 on 15 December. An eruption began at 0102 on 16 December though dark and foggy conditions prevented views of emissions. The event lasted for almost 10 minutes, and thunderous sounds were heard at the Soputan Volcano Observation Post located in Silian Raya (about 10 km SW). The conditions improved about two hours later, and a dense ash plume was visible rising 3 km above the summit and drifting SE. Incandescence from the summit was also visible. An event that began at 0540 produced dense gray-to-black ash plumes that rose as high as 7 km above the summit and drifted SE. The event lasted for 6 minutes and 10 seconds based on the seismic network. Ash plumes from events at 0743 and 0857 rose as high as 7.5 km and drifted SW. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


10 October-16 October 2018 Citation IconCite this Report

On 16 October PVMBG issued a VONA noting only white emissions at Soputan; the Aviation Color Code was lowered to Yellow.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


3 October-9 October 2018 Citation IconCite this Report

Based on satellite images, information from PVMBG, and wind model data, the Darwin VAAC reported that on 4 October ash plumes from Soputan rose to 4.6 km (15,000 ft) a.s.l. and drifted W. The Alert Level remained at 3 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 4 km, with an additional expansion to 6.5 km in WSW direction due to increased risk from a breach in the crater rim.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


26 September-2 October 2018 Citation IconCite this Report

PVMBG reported that increased seismicity at Soputan was notable on 2 October, characterized by an increased number of signals indicating emissions and avalanches (which began in September and mid-July, respectively), increased RSAM values, and a higher number of volcanic earthquakes (since September). Data from a thermal camera showed increased summit temperatures, indicating the presence of lava. The Alert Level was increased to 3 (on a scale of 1-4) on 3 October; residents and tourists were advised not to approach the craters within a radius of 4 km, with an additional expansion to 6.5 km in WSW direction due to increased risk from a breach in the crater rim. An eruption commenced at 0847 on 3 October, producing a dense ash plume that rose 4 km above the summit and drifted W and NW. Based on seismic data the event lasted six minutes. Events at 1044, 1112, and 1152 produced ash plumes that rose 2 km, 2.5 km , and 5 km above the crater rim, respectively. A thermal anomaly identified in satellite data significantly increased, and incandescent ejecta at the summit was clearly observed by residents. Avalanches of material traveled 2.5 km down the NE flank.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Badan Nacional Penanggulangan Bencana (BNPB)


20 April-26 April 2016 Citation IconCite this Report

PVMBG reported that during 1-20 April diffuse white plumes from Soputan rose as high as 100 m above the crater and drifted E. The number of volcanic earthquakes and signals indicating avalanches declined. The Alert Level was lowered to 2 (on a scale of 1-4) on 21 April; residents and tourists were advised not to approach the craters within a radius of 4 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


6 April-12 April 2016 Citation IconCite this Report

PVMBG reported that during 4-11 April diffuse white plumes from Soputan rose as high as 100 m above the crater and drifted E. Seismicity was dominated by signals indicating avalanches and emissions; avalanche signals became less intense as compared to the previous week. A few volcanic and shallow volcanic earthquakes were detected during 6 and 9-10 April. The Alert Level was lowered to 2 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 4 km. [Correction; the Alert Level remained at 3.]

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


23 March-29 March 2016 Citation IconCite this Report

PVMBG reported that during 21-28 March diffuse white plumes from Soputan rose as high as 100 m above the crater and drifted E. Seismicity was dominated by signals indicating avalanches and emissions; shallow volcanic earthquakes were detected on 21 March. The Alert Level remained at 3 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 6.5 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


24 February-1 March 2016 Citation IconCite this Report

PVMBG reported that during 22-29 February diffuse white plumes from Soputan rose as high as 75 m above the crater. Seismicity was dominated by signals indicating avalanches and emissions, though shallow volcanic and low-frequency earthquakes were also detected. The Alert Level remained at 3 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 6.5 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


10 February-16 February 2016 Citation IconCite this Report

PVMBG reported that during 9-15 February diffuse white plumes from Soputan rose as high as 200 m above the crater. Seismicity was dominated by signals indicating avalanches and emissions, though volcanic and low-frequency earthquakes were also detected. The Alert Level remained at 3 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 6.5 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


3 February-9 February 2016 Citation IconCite this Report

BNPB reported that explosions at Soputan were detected at 1300, 1437, and 2008 on 6 February; observers 10 km away saw dense reddish gray ash plumes rising 3 km above the crater. At 0106, 0204, 0311, and 0320 on 7 February Strombolian activity ejected tephra as high as 1 km above the crater. A pyroclastic flow traveled 2 km down the E flank. Thunderous sounds were reported, and dense ash plumes rose 2.5 km and drifted W. Constant tremor was detected. Ashfall was reported in multiple districts including Pasan (5 km SSE), Tombatu (16 km SSW), Belang (17 km SSE), and Ratatotok (20 km S). The Alert Level remained at 4 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank. [Correction; the Alert Level remained at 3.]

Source: Badan Nacional Penanggulangan Bencana (BNPB)


6 January-12 January 2016 Citation IconCite this Report

On 6 January BNPB reported that several explosions had been detected since the Alert Level for Soputan was raised to 3 (on a scale of 1-4) on 4 January. Strombolian activity that began at 0350 on 5 January ejected incandescent material as high as 250 m above the crater. A booming sound at 0638 was followed by a pyroclastic flow that traveled 2.5 km down the ENE flank. Ash plumes rose 6.5 km above the crater and drifted W. Several villages in the districts of West Langowan (8 km E), Tompaso (11 km NE), and East Ratahan (14 km SE) reported ashfall. Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Badan Nacional Penanggulangan Bencana (BNPB)


30 December-5 January 2016 Citation IconCite this Report

PVMBG reported that during 28 December- 1 January white plumes rose 100 m above Soputan. Photos taken during 2-3 January showed that the plumes became denser and turned light gray, rising as high as 300 m. Thermal images revealed incandescence in Puncak Crater. Seismicity increased significantly on 4 January. At 1800 PVMBG raised the Alert Level to 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank. BNPB reported that at 2053 an explosion produced a dense gray ash plume that rose as high as 2 km and drifted SE. Lava flowed down the E flank and roaring was reported. Minor ashfall occurred in Langowan (8 km ENE).

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Badan Nacional Penanggulangan Bencana (BNPB)


18 November-24 November 2015 Citation IconCite this Report

PVMBG reported that during 3-18 November white plumes were observed rising as high as 200 m above Soputan even though inclement weather sometimes obscured crater views. Seismicity was dominated by emission and avalanche signals, but was also characterized by low-frequency signals and volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 1.5 km, or 2.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


1 July-7 July 2015 Citation IconCite this Report

PVMBG reported that during June-3 July white plumes were observed rising as high as 750 m above Soputan even though inclement weather sometimes obscured crater views. Seismicity during the previous three months had declined (specifically shallow volcanic earthquakes, volcanic earthquakes, and signals indicating emissions and avalanches) but remained higher than levels recorded prior to the elevated activity which lead to the Alert Level increase on 26 December 2014. Low-frequency harmonic tremor was occasionally detected. The Alert Level was lowered to 2 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


17 June-23 June 2015 Citation IconCite this Report

PVMBG reported that during 10-17 June white plumes were observed rising as high as 500 m above Soputan even though inclement weather sometimes obscured crater views. Variable seismicity was dominated by volcanic earthquakes and signals indicating emissions and avalanches. Low-frequency harmonic tremor was occasionally detected. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


27 May-2 June 2015 Citation IconCite this Report

PVMBG reported that during 20-27 May white plumes were observed rising as high as 100 m above Soputan even though inclement weather sometimes obscured crater views. Variable seismicity was dominated by volcanic earthquakes and signals indicating emissions and avalanches. Low-frequency harmonic tremor was occasionally detected. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


13 May-19 May 2015 Citation IconCite this Report

PVMBG reported that during 6-13 May white plumes were observed rising as high as 100 m above Soputan even though inclement weather sometimes obscured crater views. Seismicity fluctuated; volcanic earthquakes continued to be recorded. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


4 March-10 March 2015 Citation IconCite this Report

Based on information from PVMBG and weather models, the Darwin VAAC reported that on 7 March an eruption at Soputan generated ash plumes that rose to an altitude of 9.1 km (30,000 ft) a.s.l. and drifted 260 km SE and SW. A thermal anomaly was detected in satellite images. BNPB noted that the eruption occurred at 1709, and produced ash plumes that rose 4.5 km above the crater and drifted E. Pyroclastic flows traveled 2.5 km down the W flank. Minor ashfall was reported in the Silian Raya district, Touluaan, Tombatu, and party in the districts of Pasan and Rataha. The Alert Level remained at 3 (on a scale of 1-4). The next day the VAAC noted that an ash plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted almost 95 km SE.

Sources: Badan Nacional Penanggulangan Bencana (BNPB); Darwin Volcanic Ash Advisory Centre (VAAC)


11 February-17 February 2015 Citation IconCite this Report

Based on information from PVMBG and weather models, the Darwin VAAC reported that during 11-12 February an eruption at Soputan generated ash plumes that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted almost 30 km SE. Ash was not identified in satellite images due to darkness and meteorological clouds.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


4 February-10 February 2015 Citation IconCite this Report

Based on satellite images and weather models, the Darwin VAAC reported that on 8 February an ash plume from Soputan rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 30 km SSE.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


28 January-3 February 2015 Citation IconCite this Report

Based on statements from PVMBG, the Darwin VAAC reported that on 2 February an ash plume from Soputan rose to an altitude of 6.1 km (20,000 ft) a.s.l. A thermal anomaly was visible in satellite images; ash was not visible at the reported altitude, but possible ash was detected to the N at 3 km (10,000 ft) a.s.l.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


21 January-27 January 2015 Citation IconCite this Report

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 21 January an ash plume from Soputan rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted over 35 km SW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


14 January-20 January 2015 Citation IconCite this Report

Based on a SIGMET, the Darwin VAAC reported that an ash plume from Soputan rose to an altitude of 5.5 km (18,000 ft) a.s.l. on 18 January. BNPB reported that an eruption at 1138 that same day generated an ash plume that rose 4 km and drifted SW; the report did not specify if 4 km was height above volcano or altitude a.s.l. Strombolian activity ejected material 500 m above the crater and incandescent avalanches of material traveled 500 m down the SW flank. The Alert Level was at 3 (on a scale of 1-4).

Sources: Badan Nacional Penanggulangan Bencana (BNPB); Darwin Volcanic Ash Advisory Centre (VAAC)


31 December-6 January 2015 Citation IconCite this Report

BNPB reported that an eruption at Soputan began at 1447 on 6 January. Observers at a nearby post reported a dense gray-to-black ash plume rising about 6.5 km above the summit and drifting ESE. Lava flows traveled 2 km down the WSW flank. The Alert Level remained at 3 (on a scale of 1-4). Based on ground reports from that same day, the Darwin VAAC reported that a significant eruption generated a plume that rose to an altitude of 8.2 km (27,000 ft) a.s.l. No ash was observed in satellite images due to weather clouds in the area.

Sources: Badan Nacional Penanggulangan Bencana (BNPB); Darwin Volcanic Ash Advisory Centre (VAAC)


6 August-12 August 2014 Citation IconCite this Report

PVMBG noted that the Alert Level for Soputan was lowered to 1 (on a scale of 1-4) on 8 August and recommended people not approach within 1.5 km of the summit or within 4 km of the summit on the W.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


30 April-6 May 2014 Citation IconCite this Report

PVMBG reported that during April diffuse white plumes from Soputan rose at most 100 m. During 30 April-1 May seismic activity significantly increased, characterized by signals indicating deep volcanic earthquakes and avalanches. On 1 May the Alert Level was raised to 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 6.5 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


12 June-18 June 2013 Citation IconCite this Report

On 14 June CVGHM reported that, after the Alert Level at Soputan was raised to 3 (on a scale of 1-4) on 19 April due to a trend of increased seismicity, the number of various types of earthquakes decreased, except for events signaling avalanches, which fluctuated during the period. No changes were observed in emissions; white plumes continued to rise at most 50 m above the crater. On 14 June the Alert Level was lowered to 2. Residents and tourists were advised not to approach the craters within a radius of 4 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


17 April-23 April 2013 Citation IconCite this Report

CVGHM reported that seismicity at Soputan increased during January-18 April and then significantly increased on 19 April. The Alert Level was raised to 3 (on a scale of 1-4) on 19 April. Visitors and residents were prohibited from going within a 6.5-km radius of the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


28 November-4 December 2012 Citation IconCite this Report

CVGHM reported that seismicity at Soputan decreased during 1-26 November. The Alert Level was lowered to 2 (on a scale of 1-4) on 27 November.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


19 September-25 September 2012 Citation IconCite this Report

Based on information from the US Air Force Weather Agency (AFWA), the Support to Aviation Control Service (SACS), and CVGHM, the Darwin VAAC reported that an ash plume from Soputan rose to an altitude of 9.1 km (30,000 ft) a.s.l. on 19 September. Later that day an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


12 September-18 September 2012 Citation IconCite this Report

Based on information from US Air Force Weather Agency (AFWA), the Darwin VAAC reported that an ash plume from Soputan rose to an altitude of 9.1 km (30,000 ft) a.s.l. on 18 September. The VAAC also noted that a sulfur dioxide alert was issued by the Support to Aviation Control Service (SACS).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


22 August-28 August 2012 Citation IconCite this Report

CVGHM reported that the Alert Level for Soputan had been lowered to 2 (on a scale of 1-4) on 26 June. Seismicity increased during 8-22 August; on 23 August volcanic earthquakes and avalanches significantly increased. White plumes rose 50-150 m above the crater. An eruption at 1936 on 26 August ejected incandescent tephra 50 m above the crater and produced a plume that rose 1 km and drifted W. The Alert Level was raised to 3.

Based on information from CVGHM, NOAA, and analysis of satellite imagery, the Darwin VAAC reported that on 27 August an ash plume rose to an altitude of 12.1 km (40,000 ft) a.s.l. and drifted 150 km W. The eruption lasted four hours. Later, a plume detected in satellite imagery rose to an altitude of 6.1 km (20,000 ft) a.s.l. On 28 August an ash plume drifted 220 km SW at an altitude of 6.1 km (20,000 ft) a.s.l.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


8 August-14 August 2012 Citation IconCite this Report

According to NASA's Earth Observatory, a satellite image acquired on 8 August showed a small volcanic plume rising from Soputan.

Source: NASA Earth Observatory


23 May-29 May 2012 Citation IconCite this Report

CVGHM reported that observers in the village of Maliku noted that during 21-27 May white plumes rose 50-150 m above the crater of Soputan. Seismicity increased significantly on 25 May. CVGHM raised the Alert Level to 3 (on a scale of 1-4) on 28 May based on visual observations and increased seismicity.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


7 September-13 September 2011 Citation IconCite this Report

CVGHM reported that seismicity at Soputan significantly decreased after the eruption on 14 August until 7 September. White plumes rose at most 200 m above the crater during 14-18 August, up to 150 m above the crater during 19-28 August, and as high as 100 m above the crater during 29 August-7 September. The Alert Level was lowered to 2 (on a scale of 1-4) on 8 September. Visitors and residents were prohibited from going within a 4-km radius of the crater, a change from the 6-km restricted zone in place when the Alert level was at 3.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


10 August-16 August 2011 Citation IconCite this Report

CVGHM reported that during 19 July-13 August white plumes from Soputan's summit crater rose 50-150 m. Seismicity fluctuated, but declined overall until 10 August. On 14 August a gray-and-white eruption plume rose 1 km above the crater. Throughout the day, two more similar plumes rose 1.3 km above the crater. Based on analysis of satellite imagery, the Darwin VAAC reported that an ash plume drifted more than 100 km W. The Alert Level was raised to 3 (on a scale of 1-4). Visitors and residents were prohibited from going within a 6-km radius of the crater.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


20 July-26 July 2011 Citation IconCite this Report

CVGHM reported that on 3 July an explosion of incandescent material from Soputan was followed by a 6-km-high ash plume and a pyroclastic flow that traveled as far as 4 km W. Later that day a dense white plume rose 50 m above the crater. On 20 July CVGHM noted that since 4 July seismicity had decreased and only diffuse white plumes rose 75 m above the crater until 18 July. The Alert Level was lowered to 2 (on a scale of 1-4) on 19 July. Visitors and residents were prohibited from going within a 4-km radius of the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


29 June-5 July 2011 Citation IconCite this Report

CVGHM reported that during June diffuse white plumes from Soputan rose 25-150 m. During 21 June-2 July seismicity increased, and on 2 July the Alert Level was raised to 3 (on a scale of 1-4). Visitors and residents were discouraged from going within a 6-km radius of the crater and climbing the volcano was prohibited. According to news articles, a CVGHM volcanologist reported that a Strombolian eruption that began on 3 July produced an ash plume that rose 6 km and drifted W. Ashfall impacted villages, trees, and vegetation downwind. Sam Ratulangi International airport in the capital of Manado was closed for three hours. Articles also stated that the Red Cross distributed about 31,000 masks to area residents.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Jakarta Globe; VIVA News; Jakarta Globe


15 October-21 October 2008 Citation IconCite this Report

CVGHM reported that the Alert Level for Soputan was lowered from 3 to 2 (on a scale of 1-4) on 21 October. CVGHM reported additional information describing the eruption that prompted the Alert Level increase on 6 October. Gray plumes rose to an altitude of 2.8 km (9,200 ft) a.s.l. and were accompanied by Strombolian activity that ejected incandescent material 50-150 m above the crater. On 7 October, white plumes rose to altitudes of 2.3-3.3 km (7,500-10,800 ft) a.s.l. Incandescent material was again ejected 50-150 m from the crater. Incandescent rockfalls traveled 500 m W. The next day, plumes rose to an altitude of 2 km (6,600 ft) a.s.l.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


1 October-7 October 2008 Citation IconCite this Report

Based on visual observations, CVGHM reported that on 6 October a "smoke" plume from Soputan rose to an altitude of 2.8 km (9,200 ft) a.s.l. and incandescent material was ejected 25 m above the summit. The Alert level was raised from 2 to 3 (on a scale of 1-4). Residents and tourists were advised not go within a 6 km radius of the summit.

Analysis of satellite imagery by the Darwin VAAC indicated that on 6 October an ash plume rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted W.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


18 June-24 June 2008 Citation IconCite this Report

CVGHM reported that the eruption of Soputan during 6-7 June caused part of the crater wall to collapse creating an opening to the W, and the diameter of the crater to increase. Ash plumes generated on 6 June drifted NW, W, SW, and as far as 60 km S. Ash deposits were about 4 cm thick in an area 5 km NW. A nearby coconut plantation reported damage to trees. During 7-18 June, seismicity decreased and white plumes at altitudes at or less than 1.8 km (5,900 ft) a.s.l. were spotted when clouds did not inhibit observations. On 18 June, the Alert Level was decreased to 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


4 June-10 June 2008 Citation IconCite this Report

CVGHM reported that during May, deformation from Soputan was detected. During 1-6 June, seismicity increased. On 6 June, a pyroclastic flow possibly generated by a rockfall avalanche traveled about 1.5 km down the E flank. The Alert Level was raised to 3 (on a scale of 1-4). Residents and tourists were advised not go within a 6 km radius of the summit.

Based on observations of satellite imagery, the Darwin VAAC reported that an ash plume rose to an altitude of 13.7 km (45,000 ft) a.s.l. on 6 June and drifted SW.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


24 October-30 October 2007 Citation IconCite this Report

Based on visual observations during clear weather, CVGHM reported that on 25, 26, 30 and 31 October, white and gray plumes from Soputan rose to altitudes of 1.8-3.3 km (5,900-10,800 ft) a.s.l. and drifted W. A lava flow traveled between 500-600 m down the W flank on 25 October and was again spotted on 30 October. The Alert Level remained at 3 (on a scale of 1-4) and villagers and tourists were advised not go within a 6 km radius of the summit.

Based on visual observations during clear weather, CVGHM reported that on 25, 26, 30 and 31 October, white and gray plumes from Soputan rose to altitudes of 1.8-3.3 km (5,900-10,800 ft) a.s.l. and drifted W. A lava flow traveled between 500-600 m down the W flank on 25 October and was again spotted on 30 October. The Alert Level remained at 3 (on a scale of 1-4) and villagers and tourists were advised not go within a 6 km radius of the summit.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


8 August-14 August 2007 Citation IconCite this Report

According to news articles, an eruption from Soputan on 14 August produced ash plumes to an altitude of 3.3 km (10,800 ft) a.s.l. Lava and rock avalanches were also observed. On 15 August, seismic activity decreased. The Alert Level remained at 3 (on a scale of 1-4).

Sources: Reuters; Antara News; Associated Press


20 June-26 June 2007 Citation IconCite this Report

Based on visual observations, CVGHM reported that during 18-25 June diffuse ash plumes from Soputan rose to an altitude of 1.8 km (5,900 ft) a.s.l. The Alert Level remained at 3 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


13 December-19 December 2006 Citation IconCite this Report

According to CVGHM, seismic signals from rockfalls increased at Soputan during 11-13 December. On 14 December, ash clouds rose to an altitude of 2 km (6,600 ft) a.s.l. and ash fell within a 15 km radius of the peak. The emissions were accompanied by thunderous noises that were heard 8 km from the peak. On 15 December the Alert Level was raised from 2 to 3 (on a scale of 1-4) due to this increase in activity.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


21 December-27 December 2005 Citation IconCite this Report

A phreatic eruption began at Soputan on 26 December around 1230 following heavy rain that contacted lava at the volcano's summit. On 27 December at 0400, a Strombolian eruption began that lasted ~50 minutes. Incandescent volcanic material was ejected ~35 m, and avalanches of volcanic material traveled as far as 750 m E. Around 0640 the avalanches became larger, as pyroclastic avalanches occurred from the edge of the lava. The avalanches extended 200 m E, and booming noises were heard as far as 5 km from the summit. The Darwin VAAC reported that an ash plume reached a height of ~5.8 km (~19,000 ft) a.s.l. and drifted SE.

As of 28 December, eruptive activity continued at Soputan, producing ash plumes to a height of ~1 km above the volcano (or 9,100 ft a.s.l.). Strombolian eruptions continued, ejecting incandescent volcanic material up to 200 m above the summit (or 6,500 ft a.s.l.). Pyroclastic avalanches traveled ~500 m E and SW. This was the fourth event at Soputan in 2005, with previous activity on 14 and 20 April, and on 12 September. The Alert Level remained at 2, since the volcano is about 11 km from the nearest settlement. Visitors are prohibited from climbing Soputan's summit and camping around Kawah Masem.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Darwin Volcanic Ash Advisory Centre (VAAC)


20 April-26 April 2005 Citation IconCite this Report

Soputan began to erupt on 20 April at 0630, with a plume reaching ~1 km above the volcano's summit (~9,100 ft a.s.l.) and drifting SE. In addition, lava fountains rose ~200 m above the volcano (~6,500 ft a.s.l.). During 20 April at 1720 to 21 April at 0900, lava fountains rose 75-100 m above the volcano (6,100-6,200 ft a.s.l.). Rapid dome growth occurred and by 21 April the lava dome had spread about 250 m E and 200 m SW. On 22 April a "white ash plume" rose ~100 m above the volcano (~6,200 ft. a.s.l.) and on 23 April a "dark gray ash" plume rose to ~150 m (~6,300 ft a.s.l.) and drifted NE. Ash eruptions continued through 24 April, producing plumes to ~300 m above the volcano (~6,800 ft a.s.l.). Soputan was at Alert Level 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


8 December-14 December 2004 Citation IconCite this Report

According to DVGHM, an eruption at Soputan on 12 December around 0050 produced an E-drifting ash cloud to ~1 km above the volcano. It was followed by a "hot cloud" that traveled about 200 m E and a lava flow that traveled SW. The eruption was preceded by an increase in tremor on 11 December and incandescence that was visible in the crater. DVGHM increased the Alert Level at Soputan to 2 (on a scale of 1-4). According to the Darwin VAAC an eruption cloud was visible on satellite imagery on 12 December at 0925 at a height of ~10.7 km a.s.l.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); The Jakarta Post; Darwin Volcanic Ash Advisory Centre (VAAC); Associated Press; Agence France-Presse (AFP)


13 October-19 October 2004 Citation IconCite this Report

According to DVGHM, volcanic tremor at Soputan began to increase to levels above normal on 18 October at 0930. In response, officials raised the Alert Level to Orange or 2 (on a scale of 1-4). Soputan erupted on 18 October at 1041, producing an E-drifting ash cloud to a height of ~600 m above the volcano's crater. At 1815 incandescence was visible reflecting 25-30 m above the crater's rim. Later that day, a "lava avalanche" traveled towards the S.

According to a news report, "ash and smoke" covered several parts of the nearby Minahasa regency and damaged hundreds of plantations along the mountain's slopes. Also, clouds of ash disrupted activities of residents in W Langowan district, where visibility fell to between 10 and 30 m. An official in the district said local homes were covered by up to 4 cm of ash. In the town of Palu, visibility decreased to 7 km. No evacuations were ordered.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); The Jakarta Post; Agence France-Presse (AFP)


3 September-9 September 2003 Citation IconCite this Report

An ash emission from Soputan on 4 September produced a cloud that rose to ~3 km a.s.l., extended ~75 km N of the summit, and was visible on satellite imagery. Soputan was at Alert Level 2 (on a scale of 1-4).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


27 August-2 September 2003 Citation IconCite this Report

On 2 September ash emissions from Soputan rose to ~2 km a.s.l. and drifted S and W. The Alert Level was raised from 2 to 3 (on a scale of 1-4).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


30 July-5 August 2003 Citation IconCite this Report

Activity decreased at Soputan after an eruption occurred on 18 July. During 21-25 July, incandescent lava on the volcano's W slope gradually cooled and on 22 July volcanic tremor stopped. Ash explosions sporadically occurred, but their density and maximum height decreased. Small-amplitude tremor was continuously recorded. As of 25 July the Alert Level at Soputan was at 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)


16 July-22 July 2003 Citation IconCite this Report

High levels of volcanic and seismic activity occurred at Soputan during mid-July. On 17 July at 1900 the Alert Level was raised to 2 (on a scale of 1-4) after incandescence was seen at the lava dome for about a day. Around 1150 the amplitude of volcanic tremor increased and at 1900 an increased level of incandescence was seen. On 18 July at 0630 incandescent lava avalanches suddenly occurred that were not proceeded by explosions or loud sounds. The avalanches were accompanied by a pyroclastic surge towards the WNW and an ash cloud that rose ~2 km above the summit. The cloud drifted N, depositing ash around the area of Tombasian, Tareran, Tompaso, Kawangkoan, Sonder, Tomohon, and Manado. The same day the Alert Level was raised to 3. On 19 July there were pyroclastic flows, ash explosions, Strombolian activity, and lava emission at the lava dome. Ash explosions continued through at least 21 July. According to news reports, some residents in villages near the volcano fled, including those in the villages of Kota Menara, Amurang, and Maliku around 10 km S of the volcano.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Terra Daily News; Darwin Volcanic Ash Advisory Centre (VAAC); The Jakarta Post


Bulletin Reports - Index

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.

08/1982 (SEAN 07:08) Explosions eject large plumes

09/1982 (SEAN 07:09) Explosive activity continues

10/1982 (SEAN 07:10) Strongest explosion since eruption began

05/1984 (SEAN 09:05) Tephra eruption

08/1984 (SEAN 09:08) Ash eruption follows local seismicity

02/1985 (SEAN 10:02) Plumes from the May and August 1984 eruptions seen on satellite images

05/1985 (SEAN 10:05) Seven-hour tephra eruption; jumbo jet flies through plume

04/1989 (SEAN 14:04) Ashfall damages houses and crops

05/1989 (SEAN 14:05) Tephra eruption follows months of tremor

05/1991 (BGVN 16:05) Explosion sounds and incandescence; frequent seismicity

06/1991 (BGVN 16:06) Ash and vapor ejected but glow ends in late May; 50 m of new lava on crater floor

11/1991 (BGVN 16:11) Incandescent ejecta; tremor

06/1993 (VSI 1993) Continued lava extrusion fills the main crater

08/1994 (BGVN 19:08) Lava dome and fumarole descriptions

01/1996 (BGVN 21:01) Vapor emission and intense tremor; possible high ash

04/1996 (BGVN 21:04) Small eruption on 15 March seen on satellite imagery

08/1996 (BGVN 21:08) Pilots reported a 4.6-km-high plume

11/1996 (BGVN 21:11) Dome glow, lava flows, and concerns about rapid dome growth

06/2000 (BGVN 25:06) During May-July 2000, continued dome growth, lava flows, and several explosions

10/2000 (BGVN 25:10) Lava dome growth continues; Strombolian and ash eruptions from summit crater

01/2002 (BGVN 27:01) Avalanche earthquakes, white plumes to 100 m through mid-July 2001

08/2003 (BGVN 28:08) Lava avalanches and ash explosions during 18-22 July 2003

10/2003 (BGVN 28:10) Ash explosion and lava flows on 31 August

11/2003 (BGVN 28:11) Avalanche earthquakes and small white gas plumes

11/2004 (BGVN 29:11) 12 December eruption covered villages with ash up to 2 cm thick

12/2004 (BGVN 29:12) Explosive eruption causes ash plume and avalanche on 18 October 2004

08/2005 (BGVN 30:08) Sporadic explosions into mid-2005; photo of 18 July pyroclastic flow

04/2006 (BGVN 31:04) Late 2005 phreatic and Strombolian eruptions; ash plume to ~ 5.8 km altitude

01/2007 (BGVN 32:01) December 2006 lava dome still venting ash

11/2007 (BGVN 32:11) Ash plumes and seismic activity continue through November 2007

09/2008 (BGVN 33:09) Eruptions with ash plumes in June and October 2008

11/2011 (BGVN 36:11) Eruptions in July and August 2011

04/2012 (BGVN 37:04) Alert level raised in May 2012 based on increased seismic activity

05/2016 (BGVN 41:05) High ash plume and lava in August-September 2012; multiple explosions, Strombolian activity, and lava flows in January-March 2015

03/2017 (BGVN 42:03) Ash plumes to over 12 km altitude, lava flows, pyroclastic flows, and Strombolian activity during January-February 2016

01/2019 (BGVN 44:01) Ash explosions on 3-4 October and 16 December 2018

05/2020 (BGVN 45:05) Minor ash emissions during 23 March and 2 April 2020




Information is preliminary and subject to change. All times are local (unless otherwise noted)


August 1982 (SEAN 07:08) Citation IconCite this Report

Explosions eject large plumes

An explosive eruption began 26 August at 1142. Ash rose to 3 km above the summit crater at 1300. Ash fell on a village 7 km SE of the volcano and lightning was observed at night. Detonations and roaring sounds followed the explosions. The 850 inhabitants of a village on the flanks of the volcano moved to nearby towns. Indonesian authorities issued a warning notice to aircraft.

An image returned by the GMS satellite at 1400 showed a fairly dense plume, ~120 km in diameter, emerging from Soputan. Four hours later, a Cathay Pacific Airlines pilot estimated that the top of the cloud was at ~15 km, well above his flight altitude. At 2000, a satellite image showed continued vigorous feeding of the plume, which extended ~700 km W from the volcano to 119°E, where it was ~350 km wide. On this image, the plume appeared to be rising to roughly the cirrus cloud level, in the upper troposphere. By midnight, feeding of the plume was weakening, and on the next image, at 0200 on 27 August, the plume was detached from the volcano.

Satellite imagery showed renewed activity shortly before 0800. A plume about the same size as the one ejected the previous day moved W. Light ashfall started at 0915 on a town about 40 km N of the volcano. Feeding of the plume continued until about 1400. An additional seismograph was installed 27 August at a site 5 km S of Soputan.

Antara radio reported a third, smaller, explosive episode 28 August. Hot ash, but no large tephra, was ejected from dawn to about midday, accompanied by thunderous sounds. Ash fell on 12 villages around the volcano, but there were no casualties. No additional explosions were reported until 16 September, when an eruption plume appeared on satellite imagery. Antara reported five explosions that day.

Geologists had visited the volcano two days before the eruption began but saw no increased surface activity. They measured fumarole temperatures of 76°, 79°, and 84°C. Soputan last erupted in 1973.

Information Contacts: A. Sudradjat, VSI; T. Baldwin, D. Haller, and M. Matson, NOAA; Antara News Agency, Jakarta.


September 1982 (SEAN 07:09) Citation IconCite this Report

Explosive activity continues

At 1700 on 16 September the GMS satellite showed a plume extending WSW from the volcano, at about the cirrus cloud level. By midnight, the plume was less dense, but feeding from the volcano appeared to be continuing. Antara radio reported that an explosion at 0120 on 17 September ejected hot ash, pebbles, and rocks 10-40 cm in diameter. Other explosions occurred at 1014, 1129, 1132, and 1715 the same day. Ejecta sometimes rose to 2 km above the summit. An ash cloud remained over the area for 18 hours. At 1100 on 18 September, a GMS image showed the cloud from a moderate to intense explosion that probably began about 1000 and ended around 1300-1400. No additional activity has been reported (table 1).

Table 1. Cloud-top temperatures for three plumes from Soputan determined by Michael Matson from NOAA 7 polar orbiting satellite images, with altitudes calculated from nearby radiosonde temperature/altitude profiles.

Date Time Temperature Altitude
26 Aug 1982 1500 -72°C 15 km
27 Aug 1982 1500 -37°C 10 km
18 Sep 1982 1330 -65°C 14 km

Information Contacts: M. Matson, D. Haller, and T. Baldwin, NOAA; Antara News Agency, Jakarta.


October 1982 (SEAN 07:10) Citation IconCite this Report

Strongest explosion since eruption began

VSI reported that explosive activity resumed at 2045 on 9 November. Ash rose to ~5 km altitude and was blown NW, falling in the city of Amurang, 20 km away. A light ashfall was also reported at the VSI's Kakaskasen Observatory, 30 km N of Soputan. Newspapers reported that ash fell 40 km from the volcano and that within hours streets near the volcano were covered by as much as 10 cm of ash, halting traffic in many areas. VSI reported that rumbling and detonations accompanied the activity, and lightning flashes were observed at 4 km altitude. The eruption ended at about 1800 on 10 November, and no rumbling was heard that night.

A VSI seismograph at Silian, 6 km S of the volcano, recorded tremors for 4 hours before the eruption. The Teledyne seismograph, set at a magnification of 2,000, indicated a maximum amplitude of 6 mm during the early morning of 10 November and 4 mm in the afternoon. Deep (tectonic) earthquakes and two shallow volcanic events also preceded the explosive activity.

The GMS satelliteshowed no activity from Soputan at 1700, but on the next image, at 2000, there was a plume extending ~150 km W from the volcano. From the plume's development and rate of drift, satellite specialists estimated that gas emission had begun shortly after 1700, or well before the first explosive activity noticed on the ground at 2045. By 0200 on 10 November, relatively diffuse, apparently low-level material was drifting N and NW, while higher-altitude ejecta formed a dense plume that moved almost directly W. Satellite data continued to show feeding of the cloud through 1400 on 10 November. On the next image, at 1700, the cloud had separated from the volcano. By 2000, a plume with dense and diffuse patches extended from about 3°N, 123°E to 4°S, 117°E, a length of more than 1,000 km, and had a maximum width of ~500 km, considerably larger than the August and September plumes.

Further Reference. Sawada, Y., 1983, Attempt on surveillance of volcanic activity by eruption cloud image from artificial satellite: Bulletin of the Volcanological Society of Japan, v. 28, p. 357-373.

Information Contacts: A. Sudradjat and Suratman, VSI; D. Haller and M. Matson, NOAA; Sinar Harapan, Jakarta; AFP.


May 1984 (SEAN 09:05) Citation IconCite this Report

Tephra eruption

Soputan erupted from 24 May at 2243 until 26 May at 0300. An ash column rose to 4 km and moved W. Ash and sand-sized tephra fell on the area W of the volcano, forming a deposit >10 cm thick over ~75 km and 1-10 cm thick over an additional 125 km. Although there were no people within the danger zone, ~3,000 were in the alert zone. About 350 spontaneously evacuated from the area, where the primary cultivation is of coconut palms. Manado and Gorontalo airports (~50 km NNE and ~200 km SW of Soputan) were closed 26 and 27 May.

As of 30 May, no volcanic earthquakes had been recorded, although two tectonic events were detected. No premonitory activity was observed.

Information Contacts: A. Sudradjat, VSI.


August 1984 (SEAN 09:08) Citation IconCite this Report

Ash eruption follows local seismicity

A 5-hour explosive eruption occurred at Soputan on 31 August, the first activity since the 24-26 May tephra ejection. VSI seismic instruments recorded a progressive increase in local seismicity beginning 6 August. On 14 August, a sequence of tremors appeared between 0400 and 0800, with amplitude increasing to 25 mm (at 2,000 magnification). VSI issued a warning to civil authorities and an alert was put into effect on the 14th. Seismicity continued 15-25 August with an irregular number of A-and B-type events, averaging 1-2/day. From 25 August until the time of the eruption, seismicity totally stopped, increasing suspicion among VSI scientists that an eruption was possible.

The eruption started at 0709 on 31 August and lasted until about noon. An ash column rose to ~6 km and moved NE. Authorities and area residents were well-prepared, and neither casualties nor an evacuation were reported. Press sources reported that the ash cloud could be seen from Manado, the provincial capital 5 km to the NNE. The ash cloud covered a large area and disrupted traffic on the trans-Sulawesi highway.

On 31 August at 1457, a visible-band image from the NOAA 7 polar orbiting satellite showed a plume extending ~450 km W from the volcano. The plume was quite dense and ~120 km wide.

Information Contacts: A. Sudradjat, VSI; M. Matson, NOAA; UPI.


February 1985 (SEAN 10:02) Citation IconCite this Report

Plumes from the May and August 1984 eruptions seen on satellite images

Yosihiro Sawada observed a series of plumes from the May and August 1984 eruptions of Soputan (table 2) on images from the GMS satellite. In 9:5, Adjat Sudradjat reported that Soputan erupted from 24 May at 2243 until 26 May at 0300, depositing tephra west of the volcano. A GMS infrared image 25 May at 2300 shows a nearly circular plume rising from the volcano. By the time of the next image, at 0500 the next day, a large eruption cloud was evident, but feeding from the volcano had ended 2 hours before. Six hours later, the plume was clearly detached from the volcano. A 5-hour explosive eruption of Soputan started 31 August at 0709 and lasted until about noon. A circular eruption column was evident less than an hour after the start of the activity (figure 1, left) and a large plume was visible 6 hours later, about 2 hours after the eruption ended (figure 1, right).

Table 2. Dimensions of plumes from Soputan determined from GMS images by Yosihiro Sawada.

Date Hour Density Width (km) Length (km) Movement direction Minimum plume temperature
25 May 1984 2300 dense 60 60 circular -79°C
26 May 1984 0500 dense 190 240 NW -82°C
26 May 1984 1100 dense 160 330 NW -70°C
26 May 1984 1700 diffuse 460 440 W --
31 Aug 1984 0800 dense 30 40 circular -74°C
31 Aug 1984 1400 dense 350 420 W -75°C
31 Aug 1984 2000 diffuse 430 660 W --
01 Sep 1984 0200 diffuse 430 360 W --
Figure (see Caption) Figure 1. GMS infrared satellite images with arrows pointing to eruption clouds from Soputan 31 August 1984 at 0800 (top), and 1400 (bottom). Courtesy of Yosihiro Sawada.

Information Contacts: Y. Sawada, MRI, Tsukuba.


May 1985 (SEAN 10:05) Citation IconCite this Report

Seven-hour tephra eruption; jumbo jet flies through plume

An ash eruption from Soputan's main crater occurred 19-20 May from 1815 to 0130. The eruption column rose to 4 km altitude, and ~2 cm of ash (fine to coarse) accumulated at villages (Kawangkoan, Langoan, Noongan, and Ratahan) 9-12 km from the crater. There were no casualties and no evacuations were necessary. The volcano has remained quiet since 22 May.

On 20 May at 0058, a jumbo jet en route from Hong Kong to Sydney, Australia, with 267 passengers and 16 crew members encountered the ash cloud ~80 km SSE of the volcano (approximately 0.5°N, 124.54°E). An orange glow discharged from the nose of the aircraft and orange sparks passed over the windshield. Engine inlets were illuminated by a white light. A light haze that smelled like burnt dust filled the cabin, and ash accumulated on flat surfaces. These effects continued for 7-8 minutes, while the aircraft remained on course at 0.85x the speed of sound, for a distance of roughly 120-135 km. The aircraft continued to Sydney, arriving 4 hours after exiting the ash cloud, and landed uneventfully. Because of damage caused by the ash cloud, it was necessary to replace all four of the aircraft's engines, other navigational components, and more than a dozen windows.

The TOMS instrument on the NIMBUS 7 polar orbiting satellite detected an area of SO2 enhancement SE of Soputan during its pass at local noon on 20 May. The area of enhancement extended from about 124.5°E to 126°E near the equator and from about 125°E to 127°E at 1.5°S with the maximum at about 1°S, 126°E.

Information Contacts: VSI; Boeing, Seattle, WA; A. Krueger, NASA/GSFC.


April 1989 (SEAN 14:04) Citation IconCite this Report

Ashfall damages houses and crops

On 22 April, Soputan erupted for the first time since May 1985 (10:05), sending ash and lapilli to 1,000-1,500 m above the summit. Newspapers, quoting VSI director Subroto Modjo, reported that the eruption consisted of three explosions (at 1027, 1535, and 1752), the second of which ejected most of the tephra. Earthquakes were recorded by a nearby seismograph and were felt 25 km away. As much as 15-20 cm of ash (carried E by the wind) fell nearby in parts of Tumaratas (11 km NE of Soputan) and Taraitak, and in Ampreng, Raringis, and Noongan. At least 500 houses were damaged and three classrooms collapsed [but see 14:5] in Noongan, a gathering hall collapsed in Paslaten Langowan (13 km ENE), and many trees, especially in the Gunung Potong forest area (7 km E) were knocked down. No ashfall was reported in Manado, 45 km NNE. Damage to buildings and crops was estimated at about $114,000. As a precaution, hazard warning maps were given to residents. . . . No casualties or additional explosions had been reported as of 26 April.

Information Contacts: OFDA; R. Austin, Englehard Engineering, USA.


May 1989 (SEAN 14:05) Citation IconCite this Report

Tephra eruption follows months of tremor

The 22 April eruption . . . was preceded by a significant increase in volcanic tremor, recorded since January. After the eruption's onset at 1027, tephra ejection continued for 45 minutes, followed by additional explosive episodes at 1535 and 1752. The eruption column rose 1-1.5 km, depositing 0.5-3 mm of lapilli and ash on the area 10-32 km E and N of Soputan. No casualties were reported, although ~50 houses and two schools were damaged. By 24 April, both eruptive activity and volcanic tremor had stopped. Volcanic tremor resumed on 6 June at 0745, but as of 9 June, surface activity was limited to weak emission of thin white fume to ~100 m above the crater.

Information Contacts: VSI.


May 1991 (BGVN 16:05) Citation IconCite this Report

Explosion sounds and incandescence; frequent seismicity

On 22-24 May... loud booming sounds and night glow were reported from the main crater. Up to 100 seismic events were recorded/6-hour period on 28 May.

Information Contacts: W. Modjo, VSI.


June 1991 (BGVN 16:06) Citation IconCite this Report

Ash and vapor ejected but glow ends in late May; 50 m of new lava on crater floor

Emissions of moderate to weak white-gray ash and vapor rose 100-300 m in June, but the weak red glow visible over the crater since 22 May, vanished on 29 May. During fieldwork on 18 June, the crater floor (50 m in diameter) was covered by ~50 m of lava (approximate volume 2.4 x 106 m3). Seismographs recorded 101 tectonic and 97 explosion earthquakes weekly, but no volcanic earthquakes were detected. An M 5.6 earthquake occurred on 20 June at 1319 in the Sulawesi Sea ~200 km NW of the volcano at 1.15°N, 122°E. The shock was felt (MM III) near Soputan.

Information Contacts: W. Modjo, VSI.


November 1991 (BGVN 16:11) Citation IconCite this Report

Incandescent ejecta; tremor

Nine episodes of volcanic tremor, lasting ~2 minutes each, and two A-type earthquakes were recorded 26-27 November. Night glow suggested that lava had been newly extruded into the crater. Similar activity occurred on 12 October. The press reported incandescent tephra ejection and an apparent lava flow on 9 December.

Information Contacts: VSI; UPI.


June 1993 (VSI 1993)

Continued lava extrusion fills the main crater

[During a visit in June (VSI, 1993), continued lava extrusion had filled the main crater. The peak of the accumulated new lava reached ~80 m above the rim of the main crater. The total volume of lava was ~28.6 million cubic meters. Activity was continuing.]

Reference. Volcanogical Survey of Indonesia, 1993, Soputan volcano: Journal of Volcanic Activity in Indonesia, v. 1, no. 1 and 2 (January-June 1993).

Information Contacts:


August 1994 (BGVN 19:08) Citation IconCite this Report

Lava dome and fumarole descriptions

The EVS mounted an expedition to visit N Sulawesi volcanoes in July. They found that the morphology of Soputan's lava dome suggested continued endogenous growth. Some other parts of their Soputan report follow.

"Many fumaroles rose in different parts of the dome, mainly in its central part and in the space between the dome's foot and the crater wall. The summit area of the dome was strewn with chaotic blocks covered by white and yellow sulfur deposits. Two other fumarolic fields were located on the SW and W parts of the lava dome. Temperature measurements showed a maximum of 140°C; gases mainly consisted of H2S, SO2, and CO2."

Information Contacts: H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland.


January 1996 (BGVN 21:01) Citation IconCite this Report

Vapor emission and intense tremor; possible high ash

Activity in late 1995 consisted of whitish vapor emission to 25-100 m above the summit. During November occasional volcanic tremors were recorded with a maximum amplitude of 1.5 mm. Aviation reports on 7 November indicated increased eruptive activity with an ash cloud rising as high as 4.5 km altitude. Satellite imagery showed a possible ash cloud extending 90 km to the SW.

On 5 December, an increase in tremor amplitude up to 5 mm followed a tectonic earthquake felt throughout the Mimahassa Peninsula on Sulawesi. The same day maximum tremor amplitude reached 200 mm and glow was observed from three points on the lava dome. About an hour later tremor reached a maximum amplitude of 40 mm. On 6 December, tremor was still being recorded, but maximum amplitude had decreased to 2 mm.

Information Contacts: Wimpy S. Tjetjep (Director), Volcanological Survey of Indonesia (VSI), Jalan Diponegoro 57, Bandung, Indonesia; Bureau of Meteorology, Northern Territory Regional Office, P.O. Box 735, Darwin, NT 0801 Australia.


April 1996 (BGVN 21:04) Citation IconCite this Report

Small eruption on 15 March seen on satellite imagery

An ash cloud to 4.5 km altitude was reported in an aviation notice on 15 March. Imagery from the GMS-5 satellite confirmed the presence of an eruption plume during 0425-0632 GMT. A small plume can be seen on the 0425 image, but there was a definite plume with arms extending W and SW by 0532. The plume was still connected to the volcano at 0632, although it was starting to dissipate. On the 0732 image the plume was still visible, but appeared to have been disconnected from the volcano for some time.

Information Contacts: Bureau of Meteorology, P.O. Box 735, Darwin NT 0801, Australia; Ian Sprod, Code 921, NASA Goddard Space Flight Center, Greenbelt MD 20771, USA.


August 1996 (BGVN 21:08) Citation IconCite this Report

Pilots reported a 4.6-km-high plume

A Notice to Airmen (NOTAM) on 10 June indicated that an ash plume rose to 4,600 m above sea level. All aircraft were required to avoid the area.

Information Contacts: Bureau of Meteorology, Northern Territory Regional Office, P.O. Box 735, Darwin, NT 0801, Australia; NOAA/NESDIS Satellite Analysis Branch, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA.


November 1996 (BGVN 21:11) Citation IconCite this Report

Dome glow, lava flows, and concerns about rapid dome growth

On 24 September observers saw glow from the lower part of Soputan's lava dome. Lava flows directed to the S and SW reached ~500 m long by 29 September. Tremor of 2-mm amplitude occurred continually around this time. If rapid dome growth continues, lava avalanches could threaten the Teluk Amurang plantation and village, located 5 and 9 km downslope, respectively.

Information Contacts: Wimpy S. Tjetjep, Volcanological Survey of Indonesia, Jalan Diponegoro No. 57, Bandung 40122, Indonesia.


June 2000 (BGVN 25:06) Citation IconCite this Report

During May-July 2000, continued dome growth, lava flows, and several explosions

This report covers the period of 1 May to 3 July 2000. Tiltmeter readings from 1-3 May showed a decrease in both the x-axis (25 µrad) and y-axis (40 µrad on the SW side of the summit, indicating deformation due to magma rising towards the surface. Magma continued to rise, but there was no increase in earthquakes registered at the Soputan Post Observatory (SPO) in Maliku. Nevertheless, seismic data from both satellite-telemetered and SPO's instruments contained an increasing trend in cumulative energy that could have been the result of tectonic earthquakes. A 5 May MR 6.5 earthquake in Banggai, ~325 km SW of Soputan, is thought to have been a precursor to a 13 May eruption.

At 1250 on 13 May, an eruption began with the ejection of incandescent materials and the emission of a thick, black ash cloud that rose 1,000 m above the summit and drifted NE. There were reports of ashfall up to 2 cm thick in the towns of Malompar and Tombatu, ~9 km S of the summit.

In the weeks following this event, seismicity remained elevated, with tectonic earthquakes dominating activity. Sporadic emissions of thin, white ash-and-steam plumes rose up to 100 m, but no explosions were reported. By 22 June, scientists were reporting several small explosions and avalanches, as well as a significant increase in the number of volcanic tremors and avalanche earthquakes.

At 1200 on 1 July, continuous tremor earthquakes reached amplitudes of 20-50 mm. Later that day, at 2232, two loud booms were heard and at 2255, lava was seen flowing up to 200 m to the W of Soputan's summit, covering over 13-14 May lava flows. Lightning was also seen around the crater and the rising plume. At 0200 on 2 July, Strombolian lava fountains were seen spewing lava 10-50 m above the crater. Later in the day, a thick gray ash plume was seen as it reached ~1,000 m altitude and slowly changed color to a dark brown. The volcano continued to produce ash plumes and persistent booming that indicated explosions were taking place although they could not be seen. The number of earthquakes reached over 100 events per day, indicating that lava dome growth continued. Observations made at both SPO and the Lokon Post Observatory, ~30 km N in Tomohon, gave the government reason to have concern for inhabitants' safety and, on 3 July, the alert level was raised from 2 to 3 (on a scale of 4).

Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).


October 2000 (BGVN 25:10) Citation IconCite this Report

Lava dome growth continues; Strombolian and ash eruptions from summit crater

This report covers the period of 1 July-31 October 2000. Activity increased and lava dome growth continued after the 13 May explosion (BGVN 25:06). By the end of June, an average of 100 earthquakes occurred per day, but the number of avalanche earthquakes decreased and fluctuated between 20 and 60 per day.

Soputan Post Observatory (SPO) at Maliku and Lokon Post Observatory (LPO) at Tomohon noted anomalous activity on 1 July. At 1200 strong tremor signals sent seismographs off-scale, but had estimated amplitudes of 20-50 mm. Visual observations at that time were hindered by haze. Workers at LPO heard a thundering sound twice at 2232, and during 2255-2303 more thundering occurred, this time accompanied by lava ejection. Lava flowed 200 m down the W flank of the volcano, and covered flows from the 13-14 May eruption.

A Strombolian eruption was observed at 0200 on 2 July with the lava fountain reaching 10-50 m above the summit. A thick white-gray ash emission reached 100 m above the summit crater and later changed to a brown color on the morning of 2 July. Further tremor earthquakes occurred with amplitudes of 30-50 mm. A dark-brown ash explosion, accompanied by a thundering sound, rose 200 m. The hazard status was set to 3 (on a scale of 1-4) on 3 July.

Reports resumed on 25-26 July, when a dense brown ash cloud rising ~1,500-3,500 m above the summit was observed along with lava fountaining to a height of 50 m. Observatory workers frequently heard rumblings from the volcano. At the end of July lava flows and lava avalanches moved down the sides of Soputan toward the SW to a distance of 400 m. Avalanche earthquakes and volcanic tremor dominated the seismic record, and an increase in deep volcanic (A-type) earthquakes took place.

Explosions issuing from the summit crater continued to be observed through the beginning of August. Ash emissions were brown-black in color, rose ~2,500 m, and were accompanied by rumbling. Lava avalanches reached distances of up to 2,000 m from the volcano, and pyroclastic flows traveled 700 m, both trending W. Seismicity remained similar to the previous week and maintained a high level. Soputan's hazard status was raised to 4 on 7 August.

Similar activity continued, and on 15 August at 2105 a dark-gray ash explosion occurred from the summit crater and rose 2,500 m. Ash from the explosion drifted SW. A Strombolian explosion followed and reached 150 m above the crater rim. The outburst was accompanied by a lava avalanche that flowed 200 m down the volcano's SW flank. Thundering that rattled windows in Maliku village 7 km away occurred coeval with the explosions. Volcanic ash advisories stated that the ash cloud from this event was carried to an altitude of 4,300 m.

Visual activity diminished until late September, but seismicity continued at similar levels until dropping in mid-September. A white, variable-density ash plume rose 25-200 m above the summit. Continuous volcanic tremor persisted until early September, and avalanche earthquakes also decreased significantly. During this period a white, variable-density ash cloud rose 50-200 m above Soputan's summit. Similar ash emissions continued until late September although cloud thickness decreased. Seismicity continued to decrease with avalanche earthquakes occurring nearly half as frequently and other earthquake types remaining similar in number.

In early October the hazard level for Soputan was decreased from 4 to 2. An ash plume continued to rise up to 200 m; in mid-October it decreased in height to 20 m above the summit crater. No further volcanic earthquakes occurred, and seismographs registered only avalanche and tectonic earthquakes for the rest of the month.

Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/).


January 2002 (BGVN 27:01) Citation IconCite this Report

Avalanche earthquakes, white plumes to 100 m through mid-July 2001

During 13 February through 15 July 2001, seismicity at Soputan was dominated by avalanche earthquakes (see table 3). Discontinuous tremor (0.5- 4 mm amplitude) was reported through most of the report period. Plumes, generally white and thin, were visible reaching 50-100 m above the summit. The Alert Level remained at 2 through at least mid-July 2001. No further reports were issued through February 2002.

Table 3. Earthquakes registered at Soputan during 13 February through 15 July 2001. No reports were issued for missing weeks. Courtesy of VSI.

Date Deep volcanic (A-type) Shallow volcanic (B-type) Avalanche Tectonic
13 Feb-19 Feb 2001 7 -- 57 8
20 Feb-26 Feb 2001 4 1 23 36
27 Feb-05 Mar 2001 -- 1 7 --
06 Mar-12 Mar 2001 6 -- 30 12
12 Mar-18 Mar 2001 4 -- 30 15
19 Mar-23 Mar 2001 5 1 56 18
02 Apr-09 Apr 2001 4 1 73 51
09 Apr-15 Apr 2001 1 1 51 17
16 Apr-23 Apr 2001 9 -- 37 30
23 Apr-29 Apr 2001 1 17 36 --
07 May-13 May 2001 -- 1 148 29
14 May-20 May 2001 1 -- 69 14
28 May-03 Jun 2001 6 -- 85 27
04 Jun-10 Jun 2001 5 -- 75 20
11 Jun-17 Jun 2001 0 0 86 18
18 Jun-24 Jun 2001 1 -- 59 14
25 Jun-01 Jul 2001 3 -- 146 18
02 Jul-08 Jul 2001 2 -- 123 34
09 Jul-15 Jul 2001 3 -- 201 48

Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI) (URL: http://www.vsi.esdm.go.id/).


August 2003 (BGVN 28:08) Citation IconCite this Report

Lava avalanches and ash explosions during 18-22 July 2003

On 18 July 2003, large glowing lava avalanches resulted in a pyroclastic surge towards the W and NW. An ash column rose up to 2,000 m above the summit, and the Alert Level was raised to 3. Lava avalanches and ash explosions continued over the next few days, but by 21 July volcanic activity had started to decrease. Night observations showed that areas where glowing lava had illuminated the W slope on 18 and 19 July became dull and gradually disappeared over the three days following the eruption. Volcanic tremor due to fluid movement also ceased as of 22 July. Ash explosions continued sporadically, but were not as thick or as high as during previous observations. On 22 July between 20 of these minor ash explosions were recorded; another 50 ash explosions were reported after that time. No volcanic earthquakes were recorded, although small-amplitude tremor (0.25 mm) was recorded continuously. After 25 July the volcano was lowered to Alert Level 2.

During the week of 28 July-3 August, lava avalanches on the W slope continued, and emissions and avalanche earthquakes dominated seismic records. In addition, a white gas plume rose 50 m.

Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi. esdm.go.id/).


October 2003 (BGVN 28:10) Citation IconCite this Report

Ash explosion and lava flows on 31 August

Increased activity during 18-22 July 2003 at Soputan consisted of frequent ash explosions and large glowing lava avalanches (BGVN 28:08). Seismicity from August through mid-October was dominated by avalanche events, with a few tectonic earthquakes (table 4). White gas emissions in this period were commonly seen rising 25-50 m above the crater, but were also reported as high as 1,000 m in late August and September. On 31 August there was ash explosion accompanied by ejection of incandescent material. The ash column reached 1,000 m above the summit. Lava flowed 750 m down the SW slope, and some descended to the N. Volcanic tremor that week (18-31 August) had an amplitude of 10-38 mm. The hazard status remained at Alert Level 2 (on a scale of 1-4) through 19 October.

Table 4. Seismicity at Soputan, 18 August-19 October 2003. Courtesy of VSI.

Date Avalanche Earthquakes Tectonic Earthquakes
18 Aug-31 Aug 2003 71 --
29 Sep-05 Oct 2003 80 12
06 Oct-12 Oct 2003 30 8
13 Oct-19 Oct 2003 62 9

Information Contacts: Dali Ahmad, Hetty Triastuty, Nia Haerani, and Suswati, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).


November 2003 (BGVN 28:11) Citation IconCite this Report

Avalanche earthquakes and small white gas plumes

Seismic activity recorded at Soputan during November was dominated by avalanche earthquakes (table 5). Frequent ash explosions occurred during July and on 31 August, when a lava flow was also seen (BGVN 28:08). Only a white gas plume reaching heights of 25-50 m was observed during 27 October-30 November. The hazard status of the volcano remained at Alert Level 2 (on a scale of 1-4).

Table 5. Seismicity at Soputan, 27 October-30 November 2003. Courtesy of VSI.

Date Avalanche Earthquakes Tectonic Earthquakes
27 Oct-02 Nov 2003 51 5
03 Nov-09 Nov 2003 35 18
10 Nov-16 Nov 2003 24 17
17 Nov-23 Nov 2003 37 7
24 Nov-30 Nov 2003 66 10

Information Contacts: Dali Ahmad, Hetty Triastuty, Nia Haerani, and Suswati, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).


November 2004 (BGVN 29:11) Citation IconCite this Report

12 December eruption covered villages with ash up to 2 cm thick

Soputan erupted again on 12 December 2004. The Directorate of Volcanology and Geological Hazard Mitigation (DVGHM) noted that an eruption on 18 October 2004 sent a cloud ~ 600 meters above the crater. The previous eruptive episode occurred during July and August 2003 (BGVN 28:08, 28:10, and 28:11). A summary of ash plumes from mid-2003 through 12 December 2004 appears in table 6. Large discrepancies appeared in reported ash column heights; with the satellite estimates about 10 times larger than ground-based estimates.

Table 6. Reported ash plume altitudes recorded from Soputan, 18 July 2003-12 December 2004. Courtesy of DVGHM and Darwin VAAC.

Date Description Source
18 Jul 2003 ~2 km above summit DVGHM
02 Sep 2003 ~2 km altitude Darwin VAAC
04 Sep 2003 ~3 km altitude (extending ~75 km N of the summit) Satellite imagery, Darwin VAAC
18 Oct 2004 ~600 m above summit DVGHM
12 Dec 2004 ~1 km above summit DVGHM
12 Dec 2004 ~10.7 km altitude Darwin VAAC

The earliest details mentioned by DVGHM regarding the 2004 activity discussed 11 December 2004, a time when the tremor tended to rise, attaining peak-to-peak amplitudes of 0.5-3.0 mm. Observers also saw incandescence at the crater's rim.

At 0046 on 12 December tremor again registered with maximum peak-to-peak amplitudes of ~ 45 mm. At 0050 on 12 December Soputan erupted, sending an ash cloud up to 1 km. This was followed by discharge of a "hot cloud" (pyroclastic flow ?) to a distance of ~ 200 m E (from 'Aeseput,' a prominent NE-flank vent that formed in 1906). A lava flow spread W and S of Soputan. Observers could hear rumbling noise and thunder from their monitoring station ~ 11 km from the crater.

White-to-gray ash went E. At 0130 on 12 December a problem arose with the seismic sensors, perhaps because the solar panel was covered with ash. By 0600 the sensor was down. At 0500 that day a hot cloud occurred with a run out distance of ~ 150 m and a height of 200 m. Activity persisted until 1030. Soputan's summit then became visually obscured by clouds, but observers could still make out a white thin-to-medium plume to 70-80 m above the crater, and incandescence.

On the 13 December at 1752 observers felt an earthquake with a magnitude of MM I-II. The seismograph was then still inoperable.

News reports. A 13 December news report in The Daily Reform Voice stated that hundreds of hectares of paddy-fields and other agricultural land to the W of the Soputan was seriously impacted by tephra.

Thomas Dobat, a German expatriat living in Indonesia and concerned about the situation, sent Bulletin editors a translation of a 13 December 2004 article on Soputan taken from the Indonesian Journal Komentar. Similar to the above report, it also noted that hundreds of villages in 13 districts in Central Minahasa and in South Minahasa suffered from tephra fall emitted on 11-12 December. These eruptions of Soputan were accompanied by heavy thunder and lightning, which were heard in the town of Amurang.

Ash fell in nearly all of Central Minahasa and in parts of South Minahasa. The result was that in all areas of Central Minahasa, especially in the town of Tondano, houses, rice-fields, and roads were ash-covered up to 2 cm thick.

Information Contacts: Directorate of Volcanology and Geological Hazard Mitigation, Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre, Australian Bureau of Meteorology (URL: http://www.bom.gov.au/info/vaac); The Daily Reform Voice; Komentar; Thomas Dobat, Lorong Jerman, Kauditan II, 95372, Sulawesi Utara, Indonesia.


December 2004 (BGVN 29:12) Citation IconCite this Report

Explosive eruption causes ash plume and avalanche on 18 October 2004

Activity at Soputan that began on 18 July 2003 (BGVN 28:08) continued with occasional ash explosions in August (BGVN 28:10 and 28:11) and through 4 September 2003 (BGVN 29:11). The report of the 12 December 2004 eruption (BGVN 29:11) also mentioned activity on 18 October. The following information from the Indonesian Directorate of Volcanology and Geological Hazard Mitigation describes that October 2004 activity in greater detail.

Volcanic tremor increased at 0930 on 18 October 2004 with amplitudes in the range of 10-40 mm. From 1026 to 1452 tremor amplitudes reached a maximum of 41 mm (over scale). At 1041 Soputan exploded, releasing a white to gray ash column as high as 600 m above the crater rim and drifting E. The explosion, along with rumbling sounds, was heard at the Post Observatory ~ 12 km from the summit. Based on increasing seismicity, the official hazard level was raised to Orange or II (on a scale of I-IV) at 1500 that day. At 1815 incandescence was visible, rising 25-30 m above the crater rim. Ash reached the Observatory at 2130, and a "lava avalanche" at 2135 traveled to the S. Tremor was recorded until 0712 on the following day, 19 October, with amplitudes of 0.5-2 mm.

A GOES-9 satellite loop of the 18 October 2004 eruption was compiled by the Darwin Volcanic Ash Advisory Centre (VAAC). Based on the dispersion patterns and infrared temperatures (minimum temperature of zero degrees), the cloud probably reached between 5,000 and 6,000 m altitude, where there was an atmospheric inversion that prevented further rise.

The Darwin VAAC also noted that a satellite image from the Terra MODIS instrument taken at 0210 UTC on 1 September 2003 showed an eruption plume during clear weather. The imaged eruption, described as a low-level cloud streaming to the SW that probably didn't rise much above the summit, occurred during a period of previously reported ash plumes and lava flow activity (BGVN 28:10).

Information Contacts: Directorate of Volcanology and Geological Hazard Mitigation, Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Andrew Tupper, Darwin Volcanic Ash Advisory Centre (VAAC), Australian Bureau of Meteorology (URL: http://www.bom.gov.au/info/vaac/soputan.shtml).


August 2005 (BGVN 30:08) Citation IconCite this Report

Sporadic explosions into mid-2005; photo of 18 July pyroclastic flow

On 18 October 2004 Soputan exploded, releasing a column of white-to-gray ash floating as high as 600 m above the crater rim and drifting E (BGVN 29:12).

On 12 December an eruption around 0050 produced an E-drifting ash cloud to ~ 1 km above the volcano. It was followed by a "hot cloud" that traveled about 200 m E towards Aeseput and a lava flow that traveled SW. The eruption was preceded by increased tremor on 11 December and visible incandescence in the crater. The Directorate of Volcanology and Geological Hazard Mitigation increased the Alert Level to 2 (on a scale of 1-4). According to the Darwin Volcanic Ash Advisory Centre an eruption cloud was visible on satellite imagery on 12 December at 0925 at an altitude of ~ 10.7 km.

On 1 February 2005 white vapor rose 50-75 m above the summit. Soputan began to erupt again at 0630 on 20 April, with a plume reaching ~ 1 km above the summit and drifting SE. In addition, lava fountains rose ~ 200 m above the volcano. From 1720 on 20 April until 0900 on 21 April, lava fountains rose 75-100 m. Rapid dome growth occurred and by 21 April the lava dome had spread about 250 m E and 200 m SW. On 22 April a "white ash plume" rose ~ 100 m, and on 23 April a dark gray ash plume rose to ~ 150 m and drifted NE. Ash eruptions through 24 April produced plumes to ~ 300 m above the volcano.

On 9 May a plume of white vapor rose 75 m above the summit. Soputan remained at Alert Level 2 through 9 May.

Further activities came to light as a result of a photograph taken during a violent eruption (figure 2). According to Syamsul Rizal, the photo was taken from Soputan volcano observatory, Maliku, ~ 12 km NW, on 18 July 2005. The eruption initially vented at the usual source on the NE flank. The pyroclastic flow that resulted was described from visible observations as less dense than those from collapses at Merapi and similar to those from Karangetang.

Figure (see Caption) Figure 2. A photo of Soputan on 18 July 2005 showing the pyroclastic flow that occurred as a result of dome collapse. Photo courtesy of DVGHM and taken by Farid Bina.

Information Contacts: Directorate of Volcanology and Geological Hazard Mitigation (DVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Andrew Tupper, Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, Northern Territory 0811, Australia (URL: http://www.bom.gov.au/info/vaac/soputan.shtml).


April 2006 (BGVN 31:04) Citation IconCite this Report

Late 2005 phreatic and Strombolian eruptions; ash plume to ~ 5.8 km altitude

Our last report covered events through July 2005 (BGVN 30:08); this report includes activity that took place in late December 2005 and also presents a discussion of the wide discrepancy of cloud-height estimates between ground, aircraft, and satellite remote-sensing observations.

Activity during 21-27 December 2005. A phreatic eruption began at Soputan on 26 December 2005 around 1230 following heavy rain. Observers concluded that rainwater contacted lava at the volcano's summit. On 27 December at 0400, a Strombolian eruption began that lasted about 50 minutes. Incandescent material was ejected ~ 35 m, and avalanches spalling off the margins of the summit traveled as far as 750 m E. Booming noises were heard 5 km from the summit. The Darwin VAAC reported that an ash plume reached a height of ~ 5.8 km altitude and drifted SE.

As of 28 December, eruptive activity continued, producing ash plumes to a height of ~ 1 km above the volcano. Strombolian eruptions ejected incandescent material up to 200 m above the summit. Pyroclastic avalanches traveled ~ 500 m E and SW. This was Soputan's fourth event in 2005, with previous activity on 14 and 20 April, and on 12 September. The Alert Level remained at 2, since the volcano is about 11 km from the nearest settlement. Visitors were prohibited from climbing Soputan's summit and from camping around Kawah Masem.

October 2005 eruption plume height discussion. The Darwin Volcanic Ash Advisory Centre and the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin – Madison collaborated to compare various estimates for the height of the 27 December cloud (BGVN 30:08). The eruption height had been initially reported at less than 6 km altitude on the 27th by an airline pilot, and 1 km above the summit (~ 2.8 km altitude) by ground observers on the 28th. Darwin VAAC, on reviewing hourly MTSAT imagery on the 27th, estimated the plume top at 15 km altitude operationally and then 12.5 km altitude in post-analysis studies.

Michael Richards of CIMSS used an established remote-sensing technique known as "CO2 slicing" (Menzel et al., 1983, Richards et al., 2006), to obtain heights of the cloudscape around Soputan after the eruption. The technique takes advantage of the fact that the emissive infrared CO2 bands available on the MODIS satellite become more transmissive with decreasing wavelength, as the bands move away from the peak wavelength of CO2 absorption at 15 µm. There were two good MODIS images obtained over the eruption on the 27th, with the first, at 0210 UTC or 1010 local time. These images were taken at close to the time of the peak cloud height observed on MTSAT imagery, and the CO2 slicing technique appears to validate the post-analyzed VAAC height of ~ 12.5 km altitude.

The different results for the height of the eruption cloud illustrate the difficulty that observers would have had viewing the cloud from any angle. Weather clouds in the tropics typically extend up to 16 km or more altitude. Cirrus cloud from a storm complex can obscure the view of a satellite for hours. On the other hand, middle-level clouds, such as altostratus, will typically lie between aircraft cruising altitudes and the ground, meaning that pilots at cruising altitude may not associate any eruption cloud with a volcano on the ground, unless the cloud is obviously volcanic. Ground observers are completely unable to view the full height of the cloud if it is penetrating through the middle-level clouds.

The appearance of the cloud on true-color, near-infrared and infrared imagery is consistent with an ice-rich (glaciated) volcanic cloud, in-line with the CVGHM account of water interactions at the ground, and also with a high water loading in the atmosphere. The extensive areas of cloud in the area hindered satellite detection of the eruption until after the pilot report of the eruption had been received.

References. Menzel, W. P., Smith, W. L., and Stewart, T. R., 1983, Improved cloud motion wind vector and altitude assignment using VAS: Journal of Applied Meteorology, v. 22, p. 377-384.

Richards, M. S., Ackerman, S. A., Pavolonis, M. J., Feltz, W. F., and Tupper, A.C., 2006, Volcanic ash cloud heights using the MODIS CO2-slicing algorithm: AMS 12th, conference on aerospace and range meteorology, Atlanta, Georgia, USA (http://ams.confex.com/ams/pdfpapers/104055.pdf).

Information Contacts: Center of Volcanology and Geological Hazard Mitigation, Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Andrew Tupper and Rebecca Patrick, Darwin Volcanic Ash Advisory Centre (VAAC), Australian Bureau of Meteorology (URL: http://www.bom.gov.au/info/vaac/soputan.shtml); Michael Richards and Wayne Feltz, Cooperative Institute for Meteorological Satellite Studies (CIMSS), University of Wisconsin, 1225 West Dayton Street, Madison, WI 53706, USA.


January 2007 (BGVN 32:01) Citation IconCite this Report

December 2006 lava dome still venting ash

Growth of the lava dome at Soputan began in 1991 (BGVN 16:06), eventually overtopping the crater rim and generating rockfalls to distances of 2-4 km downslope. Phreatic eruptions since that time have been triggered during the rainy season, and ash explosions have been frequent since 2000. An eruption and dome collapse in July 2005 sent a pyroclastic flow to a distance of 3 km from the summit. The nearest residents are at a distance of 8 km, so none of these events created hazards to the local population. Following pyroclastic avalanches and Strombolian activity in late December 2005 (BGVN 31:04), the Centre of Volcanology and Geological Hazard Mitigation (CVGHM) did not report further activity at Soputan until December 2006.

Lava dome volume in early December 2006 was reported to be 34 million cubic meters. Rockfall signals from the lava dome typically occur at a rate of about 75 per day, but the number of these events increased to 153 on 11 December, and remained high over the next two days: 120 on 12 December and 126 on the 13th. Volcanic tremor amplitude also increased on 11 December. Although thick fog hampered observations, "white smoke" was seen rising 25-30 m above the summit. At 1400 on 14 December a "thunderous" eruption was heard at the CVGHM observation post 8 km from the summit. Gray ash plumes rising 250 m above the summit caused ashfall within a 15-km radius. On 15 December the Alert Level was raised from 2 to 3 (on a scale of 1-4) due to this increase in activity.

A precautionary aviation advisory was issued by the Darwin VAAC on 18 December based on information from the CVGHM. A few hours later a plume was detected on an MTSAT image taken at 1933. The high-level eruption may have reached an altitude of 12 km altitude with the plume extending 37 km to the W.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Diponegoro 57, Bandung, Jawa Barat 40122, Indonesia (URL: http://vsi.esdm.go.id/); Jenny Farlow, Darwin Volcanic Ash Advisory Centre, Bureau of Meteorology, Australia (URL: http://www.bom.gov.au/info/vaac/).


November 2007 (BGVN 32:11) Citation IconCite this Report

Ash plumes and seismic activity continue through November 2007

Our last report on Soputan (BGVN 32:01) indicated that Soputan's lava dome was still emitting gas and generating rockfalls and ash plumes to 12 km in altitude through December 2006. This report, which includes a map (figure 3), discusses activity through November 2007.

Figure (see Caption) Figure 3. A map of northern Sulawesi island (Indonesia), with Soputan labeled. Inset shows entire island. Copyrighted map by pbi design (2002); graphic by Michael Wijaya.

According to the Center of Volcanology and Geological Hazard Mitigation (CVGHM), diffuse ash plumes rose from Soputan to an altitude of 1.8 km during 20-25 June 2007. The Alert Level remained at 3 (on a scale of 1-4), where it had been since 15 December 2006. Between 11 June and 1 July 2007 the only seismicity recorded was caused by rockfalls, with 107 events during 11-17 June, 124 events during 18-24 June, and 78 events during 25 June-1 July.

News accounts reported that Soputan erupted on 14 August, producing ash plumes that, according to the Darwin Volcanic Ash Advisory Centre (VAAC), rose to 4.6 km altitude and drifted W. Lava and rock avalanches were also observed. According to Yahoo! Canada News, volcanologist Sandy Manengke indicated that no injuries or damage were reported, but that villages along Soputan's base were covered in volcanic dust, and many residents were wearing face masks. According to Reuters, Saut Simatupang, head of Indonesia's Volcanology Survey, told the news agency that no evacuation was ordered and the Alert Level was not raised to 4 (maximum) because Soputan was unlikely to erupt in a way that would threaten the nearest village, 11 km from its crater. On 15 August seismicity decreased.

Based on observations of satellite imagery and information from CVGHM, the Darwin VAAC reported that an ash plume rose to an altitude of 4.6 km and drifted W during 14-15 August. Visual observations were made on 24-25 October and 30-31 October 2007 of white and gray plumes that rose to altitudes of 1.8-3.3 km and drifted W. In addition, based upon pilot reports and satellite imagery, the Darwin VAAC reported that on 25-26 October, ash plumes rose to 13.7 km altitude and drifted WSW. On 25 October, lava flowed 500-600 m down the W flank and flowed again on 30 October. Villagers and tourists were warned not to travel within a 6 km radius of the summit.

MODVOLC data (which is MODIS satellite thermal infrared data processed to indicate possible volcanism) is sometimes helpful in assessing lava and dome emissions at volcanoes. Alerts for 2007 appeared in August (7 alerts), October (23 alerts), and November (2 alerts). During 2006, alerts took place in December (11 alerts) and October (5).

According to CVGHM, the Alert Status was lowered from 3 to 2 on 23 November, based on a decrease in the number of earthquakes and seismic intensity, deformation measurements, and visual observations.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Diponegoro 57, Bandung, Jawa Barat 40122, Indonesia (URL: http://vsi.esdm.go.id/); Jenny Farlow, Darwin Volcanic Ash Advisory Centre, Bureau of Meteorology, Australia (URL: http://www.bom.gov.au/info/vaac/); Hawai'i Institute of Geophysics and Planetology (HIGP) Hot Spots System, University of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); Reuters (URL: http://www.reuters.com/); Yahoo! Canada News (URL: http://ca.news.yahoo.com/).


September 2008 (BGVN 33:09) Citation IconCite this Report

Eruptions with ash plumes in June and October 2008

Activity at Soputan stratovolcano was characterized in an October 2008 report by the Centre of Volcanology and Geological Hazard Mitigation (CVGHM) as ongoing growth of a lava dome since 1991. This growth has often been accompanied by ash eruptions.

Activity through 23 November 2007 included an eruption in August 2007 and several ash plumes, a lava flow, and rock avalanches (BGVN 32:11). Ash from an event in October remained in the area for about two days, affecting important flight routes. No further information was available until CVGHM reported deformation in May 2008.

According to the CVGHM, seismicity increased during 1-6 June. On 6 June, the volcano erupted, causing part of the crater wall to collapse, creating an opening to the W and increasing the diameter of the crater. A pyroclastic flow, possibly generated by a rockfall avalanche, traveled down the E flank about 1.5 km; a number of nearby villages were covered with tephra. Based on observations of satellite imagery, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that an ash plume rose to an altitude of 13.7 km on 6 June and drifted SW. Ash deposits were about 4 cm thick in an area 5 km NW, and a nearby coconut plantation reported damage to trees. The Alert Level was raised to 3 (on a scale of 1-4). Residents and tourists were advised not go within a 6 km radius of the summit.

During 7-18 June, seismicity decreased and white plumes at altitudes at or less than 1.8 km were spotted when clouds did not inhibit observations. On 18 June, the Alert Level was decreased to 2.

The next episode of seismic activity was on 6 October. Loud noises were heard and observers noted Strombolian activity that ejected incandescent material 100-150 m from the crater. CVGHM noted that a thick gray ash plume rose 2.8 km in altitude. (According to the Darwin VAAC, analysis of satellite imagery suggested that the ash plume rose to the much greater altitude of 7.6 km and drifted W.)

Based on these visual observations and on earthquake and tiltmeter deformation data, the volcano alert level was raised from 2 to 3. Residents and tourists were again advised not go within a 6 km radius of the summit.

On 7 October 2008, CVGHM reported that white plumes rose to altitudes of 2.3-3.3 km. Incandescent material was ejected 50-150 m from the crater, and incandescent rockfalls traveled 500 m W. The following day, plumes rose to an altitude of 2 km.

After 9 October, seismic activity decreased. On 20 October 2008, white and gray smoke rose from the crater to a height of 200 m above the peak. On 21 October, the Alert level was lowered from 3 to 2.

Thermal anomalies. Coinciding with the observed eruptions, MODVOLC thermal alerts were measured during 6-20 October 2008 (table 7). The set begins with 24 pixels measured at 1355 UTC (2155 local) on 6 October 2008. (If each pixel represented an area of 1-2 km2, the resulting area of thermal sources, including lava flows or other material ejected from the volcano, and possible fires, would be on the order of 25-50 km2.) After a second set of 11 alerts measured 3 hours later on 6 October, the alerts dropped to 1-2 on several days through 20 October.

[The last thermal alert detected in 2008 was at 0130 on 2 November (local time).]

Table 7. MODIS/MODVOLC satellite thermal anomalies measured at Soputan during October 2008. No anomalies were measured from the beginning of the year 2008 to 5 October. Courtesy of HIGP Thermal Alerts System.

Date Time (UTC) Pixels Satellite
06 Oct 2008 1355 24 Terra
06 Oct 2008 1655 11 Aqua
13 Oct 2008 1405 1 Terra
13 Oct 2008 1700 1 Aqua
16 Oct 2008 1435 1 Terra
16 Oct 2008 1730 2 Aqua
20 Oct 2008 1410 1 Terra
20 Oct 2008 1705 1 Aqua

Reference. International Civil Aviation Organization (ICAO), 2008, Twelfth Meeting of the Communications/Navigation/Surveillance and Meteorology Sub-Group of APANPIRG (CNS/MET/SG/12): VAAC Darwin Report July 2007-June 2008, Bangkok, Indonesia, 21-25 July 2008.

Information Contacts: 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://modis.higp.hawaii.edu/); Center of Volcanology and Geological Hazard Mitigation (CVGHM), Diponegoro 57, Bandung, Jawa Barat 40122, Indonesia (URL: http://vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Center (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, Northern Territory 0811, Australia (URL: http://www.bom.gov.au/info/vaac/).


November 2011 (BGVN 36:11) Citation IconCite this Report

Eruptions in July and August 2011

Soputan volcano, Sulawesi, Indonesia (figure 4) was relatively quiet for more than two years following our last report in September 2008 (BGVN 33:09). Thermal anomalies appeared in late May 2011 and in late June 2011, Soputan re-commenced eruptive activity. This report covers activity at Soputan during 2011 (through 2 October). Unless otherwise noted, data was reported by the Center for Volcanology and Geological Hazard Mitigation (CVGHM).

Figure (see Caption) Figure 4. A photograph of Soputan volcano, taken 6 March 2011 by Flickr account user Akhal-Téké. Index maps at left show the location of Soputan volcano on the island of Sulawesi (close-up, bottom) in Indonesia (top). Index maps modified from MapsOf.net (top) and Ginkgo Maps (bottom).

The first signs of the June-October eruption at Soputan occurred with some diffuse white plumes in June reaching 25-150 m above the crater. After an increase in seismicity during 21 June-2 July, CVGHM raised the Alert Level from 2 to 3 (on a scale from 1-4); climbing the slopes of the volcano was prohibited, and residents were discouraged from going within 6 km of Soputan's crater.

A Strombolian eruption, reported at 0603 on 3 July, generated an ash plume that rose 6 km altitude and drifted W. The eruption plume was captured in a NASA Earth Observatory satellite image (figure 5). A pyroclastic flow traveled up to 4 km W. A 10 pixel MODVOLC thermal alert was triggered at 0225 (UTC) on the same day (figure 5, table 8).

Figure (see Caption) Figure 5. A natural color satellite image of the eruptive plume generated at Soputan on 3 July 2011. The plume is seen here drifting E over Laut Maluku (Molucca Sea); the brownish color of the plume indicates that it consisted of both gas and ash. The red outline highlights the area of the 10-pixel MODVOLC thermal alert (table 2) of the same day. Courtesy of NASA Earth Observatory.

Table 8. MODVOLC thermal anomalies recorded at Soputan in 2011. A 58 pixel thermal anomaly was recorded on 2 October 2011, but was omitted due to the sun-glint angle being below 12°. The University of Hawaii states that "If a pixel has a sun-glint angle of less than 12° it is potentially contaminated by sunglint and should not be trusted." Courtesy of HIGP Thermal Alerts System, University of Hawaii. [Note that the 21 May 2011 pixel originally reported below (deleted) was actually located at some distance from the volcano in the ocean, and was most likely due to sunglint.]

Date Time (UTC) Pixels Satellite
02 Jul 2011 1700 3 Aqua
03 Jul 2011 0225 10 Terra
03 Jul 2011 0520 2 Aqua
03 Jul 2011 1740 1 Aqua
09 Jul 2011 1705 2 Aqua
08 Aug 2011 1405 1 Terra
14 Aug 2011 1345 3 Terra
14 Aug 2011 1640 3 Aqua
15 Aug 2011 0205 2 Terra
15 Aug 2011 1725 3 Aqua
23 Aug 2011 0550 2 Aqua

The Jakarta Globe reported that, due to ash fall, the Indonesian Red Cross (Pa Merah Indonesia - PMI) distributed ~ 31,000 face masks to residents (figure 6). It also reported that Sutopo Purwo Nugroho, spokesman for the National Board for Disaster Managment (BNPB), said that "there is no need for evacuation because the nearest residents are living some 8 km from the mountain." Sam Ratui International Airport was closed for 3 hours (during 1200-1500) that afternoon, according to The Jakarta Globe. Following the eruption of 3 July, seismicity decreased, and the only reported activity was dense white plumes rising to 75 m above the crater on 18 July. The Alert Level was lowered to 2 on 19 July, allowing residents to come within 4 km of the crater.

Figure (see Caption) Figure 6. Residents near Soputan with face masks they received from the Indonesian Red Cross (Pa Merah Indonesia - PMI). Courtesy of the Jakarta Globe.

Seismicity continued to decrease until 10 August. On 14 August, a plume containing ash rose to 1 km above the crater, and two other plumes rose to 1.3 km above the crater later in the day (figure 7). The Darwin Volcanic Ash Advisory Centre (VAAC) reported an ash plume that drifted more than 100 km W. The Alert Level was again raised to 3 on 14 August, once again prohibiting residents within 6 km of the crater.

Figure (see Caption) Figure 7. An ash plume from Soputan rising to greater than 1 km above the crater on 14 August 2011. In the foreground, a resident of one of the local towns is working in their field. Courtesy of Andreas/AFP-Getty Images.

Following the eruptions of 14 August, seismicity decreased significantly, and small white plumes rose above the crater. The plumes steadily decreased from 200 m high above the crater (14-18 August) to, at most, 100 m above the crater (29 August-7 September). An early morning photograph captured an eruption on 15 August, showing a small plume and lava flows down the flank of Soputan (figure 8). On 8 September, the Alert Level was lowered to 2, allowing residents to come no closer than 4 km to the crater.

Figure (see Caption) Figure 8. An early morning photograph of Soputan erupting on 15 August 2011. Lava flows down the flank of Soputan brightened the small eruptive plume billowing overhead. Courtesy of Andreas/AFP-Getty Images.

Information Contacts: Center for Volcanology and Geological Hazard Mitigation (CVGHM) Diponegoro 57, Bandung, Jawa Barat 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Akhal-Téké, Flickr photostream (URL: http://www.flickr.com/photos/51873088@N04/); MapsOf.net (URL: http://mapsof.net/); Ginkgo Maps (URL: http://www.ginkgomaps.com/); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/); 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://modis.higp.hawaii.edu/); The Jakarta Globe, Citra Graha Building 11th Floor, Suite 1102, Jakarta 12950, Indonesia (URL: http://www.thejakartaglobe.com/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, Northern Territory 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Andreas/AFP - Getty Images (URL: http://www.gettyimages.com/).


April 2012 (BGVN 37:04) Citation IconCite this Report

Alert level raised in May 2012 based on increased seismic activity

Our previous report of Soputan volcano chronicled activity during July-September 2011 (BGVN 36:11). Table 9 gives a brief history of activity and highlights activity through early May 2012. The data sources are the Darwin Volcanic Ash Advisory Centre (VAAC) for satellite monitoring of ash plumes and the Indonesian Center of Volcanology and Geological Hazard Mitigation (CVGHM) for seismic monitoring and assignment of alert levels. According to a 28 May 2012 report by CVGHM, Soputan's activities are characterized by the growth of lava domes that have been accreting steadily since 1991. The accretion of these lava domes has been frequently accompanied by ash/cinder eruptions.

Table 9. Summary of volcanic ash observations and other activity at Soputan volcano from late June 2011 through mid-2012. 'VA' refers to volcanic ash. Courtesy of Darwin VAAC and CVGHM.

Date Observations Remarks
21 Jun-02 Jul 2011 Seismic activity increased --
02 Jul 2011 -- Alert Level 2 to 3
03 Jul-04 Jul 2011 Explosive eruption of incandescent material with pyroclastic flow 4 km to W; VA plume to 4.6-14 km extending 407 km W --
04 Jul 2011 High-level eruption has ceased, dissipating --
19 Jul 2011 -- Alert Level 3 to 2
14 Aug 2011 Two eruptions; VA plume to 3.7 km extending 107 km W Alert Level 2 to 3; VA not identifiable on satellite imagery
14 Aug-07 Sep 2011 Seismic Activity significantly decreased after eruption --
08 Sep 2011 Hot air blasts of smoke from the mass of the lava dome Alert Level 3 to 2
28 May 2012 Seismic activity significantly increased Alert Level 2 to 3

On 28 May 2012, CVGHM raised the Alert Level of Soputan from 2 to 3 (on a scale of 1-4) following increasing sesimic activity. According to CVGHM, increasing activity had been observed from 21-27 May, when the volcano spewed out white smoke to heights of between 50 to 150 m above the summit. Seismicity increased significantly on 25 May.

CVGHM called on local residents to stay beyond a 6 km radius from the volcano's summit. It also warned residents of the threat of a lahar, urging people living near Ranowangko, Pentu, Lawian and Popang rivers to remain alert and aware.

MODVOLC Thermal Alerts. MODVOLC satellite thermal alerts were measured at Soputan on 2-3 July, 9 July, and 14-15 August 2011, all on the volcano's W flank. These were the first such measurements since the volcano's last eruption, during late October to early November 2008 (BGVN 33:09). Since 8 August 2011 to early March 2012, no alerts have been measured.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Volcanological Survey of Indonesia (VSI), Jalan Diponegoro 57 Bandung, Jawa Barat 40122, Indonesia (URL: http://vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, Northern Territory 0811, Australia (URL: http://www.bom.gov.au/info/vaac); MODVOLC, 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://modis.higp.hawaii.edu/); Jakarta Post (URL: http://www.thejakartapost.com).


May 2016 (BGVN 41:05) Citation IconCite this Report

High ash plume and lava in August-September 2012; multiple explosions, Strombolian activity, and lava flows in January-March 2015

The Soputan stratovolcano on the northern tip of Indonesia's island of Sulawesi has had historically observed eruptions since the 18th century, possibly earlier. During this time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924. Since the 1980's ongoing lava-dome growth has produced ash explosions, lava flows, and Strombolian eruptions every few years. The last activity with explosions, ash plumes to 6 km altitude, and a pyroclastic flow occurred between July and August 2011 (BGVN 36:11).

Monitoring is the responsibility of PVMBG (Pusat Vulkanologi dan Mitigasi Bencana Geologi) also known as CVGHM (Center for Volcanology and Geological Hazard Mitigation), and for the aviation community is within the Darwin VAAC (Volcanic Ash Advisory Center) region. This report covers two eruptive episodes; renewed seismic activity in May 2012 preceded a short eruption between August and September 2012, and repeated explosions with lava flows and incandescent material were recorded between January and March 2015.

The first eruptive episode began with an explosion on 26 August 2012 and a 12.2 km altitude ash plume. MODVOLC thermal anomalies were recorded on 26 and 28 August, and a significant SO2 anomaly was visible on 27 August. A second explosion on 18 September generated a plume to 9.1 km altitude, lava flows, and incandescent material; MODVOLC thermal anomalies persisted from 18 through 22 September 2012. Soputan was then quiet until January 2015 when it erupted repeatedly between 6 January and 8 March 2015 with ash plumes, lava flows, and Strombolian activity. Substantial MODVOLC thermal anomalies were recorded on 21 January, 2-3 and 12-13 February, and 7-9 March 2015. Seismicity remained elevated through July 2015.

Activity during 2012. During 21-27 May 2012 observers in the village of Maliku (12 km NW of Soputan) noted white steam plumes rising 50-150 m above the crater. A sharp increase in the number of seismic events began on 25 May, prompting CVGHM to increase the Alert Level to 3 on 28 May 2012. The Alert Level was lowered back to 2 on 26 June. During most of August, observers noted white steam plumes rising 50-200 m above the summit crater. Each week during 1-25 August there was an increase in the number of deep volcanic earthquakes and earthquakes indicating avalanches.

On 26 August 2012 at 1936 local time, CVGHM reported visual observation of a large eruption with an ash plume rising to 1,000 m above the summit and drifting W; they raised the Alert Level to 3. It was accompanied by a burst of incandescent material that rose 50 m above the summit. Darwin VAAC issued an ash advisory shortly after the eruption indicating that a large plume was observed in satellite imagery rising to 12.2 km altitude and extending 150 km W. They noted that the eruption continued for four hours, and the plume was moving W at around 80 km/hour. After 24 hours, the plume was still visible in satellite imagery, at 6.1 km altitude and extending around 220 km SW. MODVOLC thermal anomalies were recorded on 26 and 28 August. NASA's Global SO2 monitoring program at Goddard Space Flight Center (GSFC) captured a significant SO2 plume from Soputan on 27 August from the OMI instrument on the Aura satellite (figure 9).

Figure (see Caption) Figure 9. SO2 plume drifting W from Soputan on 27 August 2012, the day after an explosion that produced an ash plume to over 12 km altitude. Courtesy of NASA/GSFC.

Another eruption during 18-19 September 2012 included an ash explosion, lava flows, and incandescent material, according to CVGHM. Based on information from the US Air Force Weather Agency (AFWA), the Darwin VAAC reported that an ash plume rose to an altitude of 9.1 km on 18 September. The ash cloud dispersed to the W between the summit elevation (1,785 m) and 3.7 km altitude, and to the NNE between 3.7 and 9.1 km altitude. Thermally anomalous pixels were recorded by the MODVOLC thermal alert system from 18 to 20 September, followed by a two-pixel anomaly on 22 September and a single-pixel anomaly on 27 September.

Activity during 2013 and 2014. Seismicity decreased in November 2012 to levels that allowed CVGHM to reduce the Alert Level from 3 to 2. From January through March 2013, the number of seismic events from avalanches increased significantly. On 19 April 2013 a sharp increase in the number of deep volcanic earthquake events caused CVGHM to raise the Alert Level again to 3. They also observed steam plumes rising to 400 m above the summit, higher than usual. No eruption occurred, and the steady decrease in seismicity in the following months caused CVGHM to lower the Alert Level back to 2 on 14 June 2013. On 1 May 2014 the Alert Level was again raised to 3 based on increases in seismicity, but it was lowered to 2 on 8 August 2014 after a steady decrease in seismicity and steam plumes rising less than 200 m from the summit. Thermally anomalous pixels detected by MODVOLC in October 2014 were located 5-10 km W of the summit and not likely related to volcanic activity. No explosions or other eruptive activity was reported by CVGHM during 2013 or 2014.

Activity during 2015. Observations in December 2014 indicated steam plumes rising less than 200 m above the summit. Low seismicity was detected until the third week of the month when there was a significant increase in the number of seismic events, prompting an increase in the Alert Level to 3 on 26 December 2014.

CVGHM reported to BNPB (Badan Nasional Penanggulangan Bencana, Indonesia's National Board for Disaster Management) that on 6 January 2015 an eruption occurred with an ash plume that rose 6.5 km above the summit and drifted ESE. A lava flow was also observed moving 2,000 m down the WSW flank of the volcano. A single MODVOLC thermal pixel was recorded on 7 January on the W flank. Based on ground reports from that same day, the Darwin VAAC noted a significant eruption that generated a plume to an altitude of 8.2 km, but ash was not confirmed in satellite images due to weather clouds in the area.

Seven more explosions were reported between 18 January and 7 March 2015. An explosion was witnessed on 18 January with a plume reported by CVGHM rising to 4 km and drifting SW. Strombolian explosions ejected incandescent material 500 m above the crater and down onto the flanks, and lava was seen flowing 500 m SW down the flanks. A single MODVOLC pixel was recorded on 18 January. On 20 January a plume rose to 3 km altitude and drifted 45 km SW as reported by Darwin VAAC. The explosion on 21 January generated a 3.7-km-altitude ash plume and was accompanied by a multi-pixel MODVOLC thermal anomaly.

A large 6.1-km-altitude plume on 1 February also coincided with a substantial MODVOLC thermal anomaly that persisted during 1-3 February. A smaller explosion on 8 February produced an ash plume that rose to 3 km and drifted 30 km SSE. CVGHM reported an eruption late on 10 February with an ash plume to 3.7 km that was observed on satellite imagery by Darwin VAAC early on 12 February. It also coincided with a significant multi-pixel MODVOLC thermal anomaly from 10-15 February.

Based on information from CVGHM and weather models, the Darwin VAAC reported that on 7 March an explosion generated large ash plumes that rose to an altitude of 9.1 km and drifted 260 km SE and SW. BNPB noted that pyroclastic flows traveled 2.5 km down the W flank and minor ashfall was reported in Silian Raya (10 km WSW), Touluaan (13 km SW), Tombatu (17 km SSW), and in the districts of Pasan (5 km SSW) and Ratahan (10 km SE). A substantial MODVOLC thermal anomaly first appeared on the N flanks on 7 March and lasted through 10 March (figure 10). The Alert Level remained at 3 (on a scale of 1-4). The next day, the VAAC noted that an ash plume rose to an altitude of 3.7 km and drifted almost 95 km SE before dissipating.

Figure (see Caption) Figure 10. MODVOLC thermal anomalies at Soputan between 7 and 10 March 2015. Darwin VAAC reported a plume to 9.1 km on 7 March. CVGHM reported pyroclastic flows on the W flank and minor ashfall to the S and W on 7 March, followed by another ash emission on 8 March. The three separated pixels to the right (east) of Soputan may be agriculture related, but the others are likely related to the eruption. Green gridlines represent decimal latitude and longitude. Courtesy of MODVOLC.

Seismicity continued to be variable through June 2015, with slowly declining frequency and magnitude of earthquakes (figure 11), and variable heights of steam plumes to 750 m. On 3 July 2015 CVGHM lowered the Alert Level to 2.

Figure (see Caption) Figure 11. Volcanic earthquake energy equivalence chart for Soputan between 1 January 2014 and 26 May 2015. No ash explosions were reported between May and June 2014, during the first spike in energy release, but they were reported eight times between 6 January and 7 March 2015. Courtesy of CVGHM (Soputan Report, 29 May 2015).

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); U.S. Air Force Weather Agency (AFWA)/XOGM, Offutt Air Force Base, NE 68113, USA; Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC 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://modis.higp.hawaii.edu/, http://modis.higp.hawaii.edu/cgi-bin/modisnew.cgi); Badan Nasional Penanggulangan Bencana (BNPB), National Disaster Management Agency, Graha BNPB - Jl. Scout Kav.38, East Jakarta 13120, Indonesia (URL: http://www.bnpb.go.id/).


March 2017 (BGVN 42:03) Citation IconCite this Report

Ash plumes to over 12 km altitude, lava flows, pyroclastic flows, and Strombolian activity during January-February 2016

Soputan stratovolcano on the northern tip of Indonesia's island of Sulawesi has had historically observed eruptions since the 18th century, possibly earlier. The locus of eruptions has included both the summit crater and a NE-flank vent that was active during 1906-1924. Since the 1980's, continuing lava-dome growth has been punctuated by ash explosions, lava flows, and Strombolian eruptions every few years. When these events last occurred between January and March 2015, they were accompanied by strong thermal anomalies and elevated seismicity which continued into early July 2015 (BGVN 41:05). This report covers the period from July 2015 through September 2016.

Increased seismicity in November 2015 signaled the beginning of a new eruptive episode, with explosions in January and February 2016. Soputan is monitored by PVMBG (Pusat Vulkanologi dan Mitigasi Bencana Geologi), Badan Nasional Penanggulangan Bencana (BNPB) which is the Indonesian National Disaster Management Agency, and aviation alerts are managed by the Darwin VAAC (Volcanic Ash Advisory Center). Information is also provided by the University of Hawaii's MODVOLC Thermal Alert System and the MIROVA project, an Italian collaboration; both groups analyze the MODIS satellite data for thermal anomalies related to volcanoes.

Soputan erupted a significant ash plume to over 12 km altitude on 4 January 2016 after a few months of increasing seismicity. Lava flows, Strombolian eruptions, and a pyroclastic flow were observed the next day. Another large ash plume to 13 km altitude occurred on 14 January. A series of explosions beginning on 6 February resulted in more ash plumes, lava flows, and Strombolian eruptions for about 24 hours, after which activity decreased significantly. Several villages within 20 km reported ashfall from these events. The last reported activity was on 7 February 2016, although thermal anomaly data extended well into April. Seismicity had declined significantly by mid-April when the Alert Level was lowered.

Activity during July-November 2015. PVMBG lowered the Alert Level to II (second lowest on a four-level scale) on 3 July 2015, citing reduced harmonic tremor and stable RSAM (Real-time Seismic amplitude measurements) at background levels compared with the eruptive activity between January and March 2015. They did not issue another update until 3 November 2015.

MODVOLC thermal alert information from MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data indicated anomalies in the vicinity of Soputan twice in September and four times in October 2015, but the locations were far enough from the volcano to suggest that they were not related to volcanic activity. This is corroborated with the MIROVA (Middle InfraRed Observation of Volcanic Activity) data from this same period which also recorded increases in Volcanic Radiative Power (VRP) in September and October. The locations indicated by MIROVA are mostly greater than 5 km from the summit, also suggesting a non-volcanic source (figure 12).

Figure (see Caption) Figure 12. MIROVA analysis of MODIS data for 6 September 2015 through 6 September 2016 for Soputan. Moderate to High values in September and October 2015 are noted in black, indicating sources more than 5 km from the volcano and likely not related to eruptive activity. Low values in blue between 6 September and mid-December are from an unknown source within 5 km of the summit. The spikes on 4-6 January 2016 and 6-8 February correspond to observed ash plumes, lava flows, pyroclastic flows, and Strombolian eruptions reported by PVMBG. Courtesy of MIROVA.

Additional thermal anomaly signals in the MIROVA data from mid-September through early December 2015 appear to be sourced within 5 km of the summit (figure 12), but their origin is unknown. PVMBG makes no mention of active eruptions or ash plumes during this time. PVMBG maintained the Level II alert status and documented clear skies with diffuse white steam plumes rising between 20 and 200 m from the summit crater during the last half of October and November, unchanged since July. They noted, however, that the frequency of several types of earthquakes began a gradual increase in the middle of October.

Activity during January-September 2016. Elevated seismicity continued until 4 January 2016. Photos taken on 3 and 4 January showed an increase in the density of the white-to-light-gray emissions rising to 300 m above the summit (figure 13).

Figure (see Caption) Figure 13. Emissions (white to light-gray) rise from Soputan on 3 January 2016, about 24 hours prior to a significant ash eruption (colors adjusted from original image). Courtesy of PVMBG (Soputan activity report through 4 January 2016).

Dense reddish-white emissions rose 300 m above the summit early in the day on 4 January. A thermal image taken that day indicated that lava was present at the summit; PVMBG raised the Alert Level to III. Seismic amplitude (RSAM) values had also increased sharply in the preceding 12 hours, and tilt measurement data indicated significant inflation of the volcano. BNPB reported an ash eruption at 2053 local time, with a plume rising 2 km from the summit and drifting SE, and incandescent lava flowing down the E flank. Minor ashfall was reported in Langowan (12 km NE) in the Minahasa District. The Darwin VAAC raised the Aviation Color Code (ACC) to Red at 2230 local time and reported an ash plume at 12.8 km altitude drifting west 30 minutes later. This was followed in the next 24 hours by two more plumes that rose to 10.6 km and drifted NW to NE (figure 14). Continuous emissions rising to about 3.7 km were observed until early 7 January.

Figure (see Caption) Figure 14. Soputan eruption during the morning hours of 5 January 2016 (local time). Photograph location uncertain but likely taken in the vicinity of Ronoketang, about 12 km S. Courtesy of PVMBG.

A Strombolian phase early on 5 January lasted about 40 minutes and sent incandescent material 250 m high, according to BNPB. Sounds resembling thunder followed, and then a pyroclastic flow traveled 2.5 km down the ENE flank. An ash cloud rose 6.5 km above the summit crater rim (8.3 km altitude) and drifted W. Several villages in the districts of West Langowan (8 km E), Tompaso (11 km NE), and East Ratahan (14 km SE) reported ashfall.

MODVOLC thermal alert pixels likely associated with the eruption were reported during 6-8 January. A small cluster on 10 January located on the NE flank possibly indicated flowing or cooling lava. The Darwin VAAC reported another large ash plume on 14 January that rose to 13.7 km and drifted 45 km NE before dissipating.

A new series of explosions began on 6 February 2016. Ash plumes rose to 7 km altitude, later dropping to the range of 4.3-6 km, with continuous emissions drifting up to 75 km WSW through the next day. PVMBG reported lava flows on the N and E flanks; Strombolian explosions witnessed from the observation post in the village of Silian (about 10 km from the volcano) ejected material 300 m high. BNPB reported Strombolian activity on 7 February with ejected material as high as 1,000 m above the summit crater. Pyroclastic flows were also observed moving up to 2 km down the E flank. Seismic amplitudes remained high, indicating the active movement of magma within the volcano. Ashfall was reported in multiple districts including Pasan (5 km SSE), Tombatu (16 km SSW), Belang (17 km SSE), and Ratatotok (20 km S). The MODIS thermal anomaly data resulted in a very strong (32 pixel) MODVOLC thermal alert on 6 February. This corresponded with the Volcanic Radiative Power (VRP) spike presented in the MIROVA information for the same period (figure 12).

For the rest of February, only diffuse white steam plumes rose 75 m, except for a 700-m-high plume reported on 12 February by PVMBG; three MODVOLC thermal alert pixels were recorded on 11 and one on 13 February. Minor steam emissions rose to 100 m at the end of March, but the frequency of earthquakes associated with avalanches and low-frequency earthquakes were still elevated above background levels. The intensity of the avalanche-related earthquakes began to decline in the second week in April according to PVMBG. No incandescence was observed at the summit by the third week of April, and the decreasing frequency and amplitude of the earthquakes led PVMBG to lower the Alert Level to II on 21 April 2016. Between May and mid-September 2016, emissions from the volcano were characterized by white plumes of variable density ranging from 20 to 300 m above the crater and seismicity remained low (figure 15). The Alert Level remained at II.

Figure (see Caption) Figure 15. Seismicity at Soputan from 1 January 2015 through 14 September 2016. Dates of eruptive events are shown with red bars. Vertical axis on all graphs is daily frequency. LETUSAN is eruption, vertical axis on the right is height in meters above summit of ash plume observed by PVMBG; HEMBUSAN is emission related seismicity; GUGURAN is seismicity associated with rock avalanches; VULKANIK DANGKAL are shallow volcanic earthquakes; VULKANIK DALAM are deep volcanic earthquakes; TECTONIK JAUH are remote tectonic earthquakes. Courtesy of PVMBG (Soputan Report of activity through 14 September 2016).

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Badan Nasional Penanggulangan Bencana (BNPB), National Disaster Management Agency, Graha BNPB - Jl. Scout Kav.38 East Jakarta 13120 (URL: http://www.bnpb.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC 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://modis.higp.hawaii.edu/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/).


January 2019 (BGVN 44:01) Citation IconCite this Report

Ash explosions on 3-4 October and 16 December 2018

Soputan typically erupts every few years with ash explosions, lava flows, and Strombolian eruptions (SEAN 07:08, BGVN 42:03). After a short eruptive period during January-February 2016, the volcano quieted, with only occasional steam plumes and low seismicity. An ash explosion on 3 October 2018 marked the beginning of a new eruption. The volcano is monitored by the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG). This report discusses activity during September through December 2018.

According to PVMBG, increased seismicity at Soputan was notable on 2 October 2018, characterized by an increased number of signals indicating emissions and avalanches (which began in September and mid-July, respectively), increased Real-time Seismic-Amplitude Measurement (RSAM) values, and a higher number of volcanic earthquakes (since September). Data from a thermal camera showed increased summit temperatures, interpreted as indicating the presence of lava. The Alert Level was increased to 3 (on a scale of 1-4) on 3 October; people were advised not to approach the craters within a radius of 4 km, with an additional expansion to 6.5 km on the WSW flank due to increased risk from a breach in the crater rim.

An eruption at 0847 on 3 October produced a dense ash plume that rose 4 km above the summit and drifted W and NW (figure 16). Based on seismic data the event lasted six minutes. Events at 1044, 1112, and 1152 produced ash plumes that rose 2, 2.5, and 5 km above the crater rim, respectively. A thermal anomaly identified in satellite data significantly increased, and incandescent ejecta at the summit was clearly observed by residents. Avalanches of material traveled 2.5 km down the NE flank.

Figure (see Caption) Figure 16. An ash plume from Soputan on 3 October 2018, as seen from Tomohon (25 km NNE). Courtesy of AP Photo/Hetty Andih.

Based on satellite images, information from PVMBG, and wind model data, the Darwin Volcanic Ash Advisory Center (VAAC) reported that on 4 October ash plumes rose to an altitude of 4.6 km and drifted W. On 16 October, PVMBG issued a Volcano Observatory Notice for Aviation (VONA) that noted only white emissions; consequently, the Aviation Color Code was lowered to Yellow.

According to PVMBG, seismic activity rapidly and significantly increased at 1700 on 15 December. An eruption began at 0102 on 16 December, though dark and foggy conditions prevented views of emissions. The event lasted for almost 10 minutes, and thunderous sounds were heard at the Soputan Volcano Observation Post located in Silian Raya (about 10 km SW). The conditions improved about two hours later, and a dense ash plume was visible, rising 3 km above the summit and drifting SE. Incandescence from the summit was also visible. An event that began at 0540 produced dense gray-to-black ash plumes that rose as high as 7 km above the summit (summit elevation is 1,785 m) and drifted SE. The event lasted for 6 minutes and 10 seconds based on the seismic network. Ash plumes from events at 0743 and 0857 rose as high as 7.5 km and drifted SW.

Satellite data. Thermal anomalies, based on MODIS satellite instruments analyzed using the MODVOLC algorithm, were observed during two days in September (14 and 30 September), seven days in October, and lastly on 8 November 2018. Pixel numbers peaked during 3-7 October (six pixels on 3 October). The MIROVA (Middle InfraRed Observation of Volcanic Activity) volcano hotspot detection system, also based on analysis of MODIS data, detected numerous hotspots within 5 km of the volcano during the reporting period. Significant sulfur dioxide levels near the volcano were recorded by NASA's satellite-borne ozone instruments on or just after the 3 October and 16 December explosions.

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Badan Nasional Penanggulangan Bencana (BNPB), National Disaster Management Agency, Graha BNPB - Jl. Scout Kav.38, East Jakarta 13120, Indonesia (URL: http://www.bnpb.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC 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://modis.higp.hawaii.edu/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center (NASA/GSFC), 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); Associated Press (URL: http://www.ap.org/).


May 2020 (BGVN 45:05) Citation IconCite this Report

Minor ash emissions during 23 March and 2 April 2020

Soputan is a stratovolcano located in the northern arm of Sulawesi Island, Indonesia. Previous eruptive periods were characterized by ash explosions, lava flows, and Strombolian eruptions. The most recent eruption occurred during October-December 2018, which consisted mostly of ash plumes and some summit incandescence (BGVN 44:01). This report updates information for January 2019-April 2020 characterized by two ash plumes and gas-and-steam emissions. The primary source of information come from the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and the Darwin Volcanic Ash Advisory Center (VAAC).

Activity during January 2019-April 2020 was relatively low; three faint thermal anomalies were observed at the summit at Soputan in satellite imagery for a total of three days on 2 and 4 January, and 1 October 2019 (figure 17). The MIROVA (Middle InfraRed Observation of Volcanic Activity) based on analysis of MODIS data detected 12 distal hotspots and six low-power hotspots within 5 km of the summit during August to early October 2019. A single distal thermal hotspot was detected in early March 2020. In March, activity primarily consisted of white to gray gas-and-steam plumes that rose 20-100 m above the crater, according to PVMBG. The Darwin VAAC issued a notice on 23 March 2020 that reported an ash plume rose to 4.3 km altitude; minor ash emissions had been visible in a webcam image the previous day (figure 18). A second notice was issued on 2 April, where an ash plume was observed rising 2.1 km altitude and drifting W.

Figure (see Caption) Figure 17. Sentinel-2 thermal satellite imagery detected a total of three thermal hotspots (bright yellow-orange) at the summit of Soputan on 2 and 4 January and 1 October 2019. Sentinel-2 atmospheric penetration (bands 12, 11, 8A) images courtesy of Sentinel Hub Playground.
Figure (see Caption) Figure 18. Minor ash emissions were seen rising from Soputan on 22 March 2020. Courtesy of MAGMA Indonesia.

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); MAGMA Indonesia, Kementerian Energi dan Sumber Daya Mineral (URL: https://magma.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).

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.

Eruptive History

There is data available for 41 confirmed Holocene eruptive periods.

2020 Mar 23 - 2020 Apr 2 Confirmed Eruption VEI: 2

Episode 1 | Eruption
2020 Mar 23 - 2020 Apr 2 Evidence from Observations: Reported

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
2020 Mar 23    - - - - VEI (Explosivity Index) Ash plume 4.3 km altitude

2018 Oct 2 - 2018 Dec 16 Confirmed Eruption VEI: 3

Episode 1 | Eruption
2018 Oct 2 - 2018 Dec 16 Evidence from Observations: Reported
 Increased seismicity was notable on 2 October 2018. Data from a thermal camera showed increased summit temperatures, indicating the presence of lava. An eruption began at 0847 on 3 October, producing a dense ash plume that rose 4 km above the summit. Events at 1044, 1112, and 1152 produced ash plumes that rose 2, 2.5, and 5 km above the crater rim, respectively. A thermal anomaly identified in satellite data significantly increased, and incandescent ejecta at the summit was clearly observed by residents. Avalanches of material traveled 2.5 km down the NE flank. On 4 October ash plumes rose to an altitude of 4.6 km and drifted W. <br><br> Seismic activity rapidly increased at 1700 on 15 December. An eruption began at 0102 on 16 December, though dark and foggy conditions prevented views of emissions. The event lasted for almost 10 minutes, and thunderous sounds were heard about 10 km SW. The conditions improved about two hours later, and a dense ash plume was visible, rising 3 km above the summit and drifting SE. Incandescence from the summit was also visible. An event that began at 0540 produced dense gray-to-black ash plumes that rose as high as 7 km above the summit and drifted SE. The event lasted for 6 minutes and 10 seconds based on the seismic network. Ash plumes from events at 0743 and 0857 rose as high as 7.5 km and drifted SW.

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
2018 Oct 3 2018 Oct 4 Explosion An eruption at 0847 on 3 October produced a dense ash plume that rose 4 km above the summit and drifted W and NW. Based on seismic data the event lasted six minutes. Events at 1044, 1112, and 1152 produced ash plumes that rose 2, 2.5, and 5 km above the crater rim, respectively. On 4 October ash plumes rose to an altitude of 4.6 km and drifted W.
2018 Dec 15    - - - - VEI (Explosivity Index) VEI 3.
2018 Dec 16    - - - - Explosion An eruption began at 0102 on 16 December, though dark and foggy conditions prevented views of emissions; the event lasted for almost 10 minutes. When conditions improved about two hours later a dense ash plume was visible, rising 3 km above the summit and drifting SE. An event that began at 0540 produced dense gray-to-black ash plumes that rose as high as 7 km above the summit and drifted SE; the event lasted for 6 minutes and 10 seconds. Ash plumes from events at 0743 and 0857 rose as high as 7.5 km and drifted SW.

2016 Jan 2 - 2016 Feb 7 Confirmed Eruption VEI: 3

Episode 1 | Eruption Puncak Crater
2016 Jan 2 - 2016 Feb 7 Evidence from Observations: Reported

List of 37 Events for Episode 1 at Puncak Crater

Start Date End Date Event Type Event Remarks
2016 Jan 2 2016 Jan 3 Ash Plume PVMBG reported that during 28 December- 1 January white plumes rose 100 m above Soputan. Photos taken during 2-3 January showed that the plumes became denser and turned light gray, rising as high as 300 m.
2016 Jan 2 2016 Jan 3 Incandescence Thermal images revealed incandescence in Puncak Crater.
2016 Jan 4    - - - - Seismicity (volcanic) Seismicity increased significantly.
2016 Jan 4    - - - - Explosion BNPB reported that at 2053 an explosion produced a dense gray ash plume that rose as high as 2 km and drifted SE.
2016 Jan 4    - - - - Ash Plume BNPB reported that at 2053 an explosion produced a dense gray ash plume that rose as high as 2 km and drifted SE.
2016 Jan 4    - - - - Ash Plume The Darwin VAAC raised the Aviation Color Code (ACC) to Red at 2230 local time and reported an ash plume at 12.8 km altitude drifting west 30 minutes later.
2016 Jan 4    - - - - Ashfall Minor ashfall occurred in Langowan (8 km ENE).
2016 Jan 4    - - - - Lava flow Lava flowed down the E flank and roaring was reported.
2016 Jan 4    - - - - Thermal Anomaly A thermal image indicated that lava was present at the summit.
2016 Jan 4    - - - - Audible Sounds Lava flowed down the E flank and roaring was reported.
2016 Jan 4    - - - - Deformation (inflation) Tilt measurement data indicated significant inflation of the volcano.
2016 Jan 4    - - - - VEI (Explosivity Index) VEI 3
2016 Jan 5    - - - - Ash Plume The large explosion on 4 January was followed in the next 24 hours by two more plumes that rose to 10.6 km altitude and drifted NW to NE.
2016 Jan 5 2016 Jan 7 Ash Plume Ash plumes rose 6.5 km above the crater and drifted W. Continuous emissions rising to about 3.7 km altitude were observed until early on 7 January.
2016 Jan 5    - - - - Pyroclastic flow A booming sound at 0638 was followed by a pyroclastic flow that traveled 2.5 km down the ENE flank.
2016 Jan 5    - - - - Ashfall Several villages in the districts of West Langowan (8 km E), Tompaso (11 km NE), and East Ratahan (14 km SE) reported ashfall.
2016 Jan 5    - - - - Incandescent ejecta Strombolian activity that began at 0350 ejected incandescent material as high as 250 m above the crater.
2016 Jan 5    - - - - Audible Sounds A booming sound at 0638 was followed by a pyroclastic flow that traveled 2.5 km down the ENE flank.
2016 Jan 5    - - - - VEI (Explosivity Index) VEI 3
2016 Jan 7 2016 Jan 10 Thermal Anomaly Six MODVOLC thermal alerts were issued.
2016 Jan 14    - - - - Ash Plume The Darwin VAAC reported another large ash plume that rose to 13.7 km altitude and drifted 45 km NE before dissipating.
2016 Jan 14    - - - - VEI (Explosivity Index) VEI 3
2016 Feb 6    - - - - Explosion BNPB reported that explosions were detected at 1300, 1437, and 2008.
2016 Feb 6    - - - - Ash Plume Observers 10 km away saw dense reddish gray ash plumes rising 3 km above the crater.
2016 Feb 6 2016 Feb 7 Ash Plume Ash plumes rose to 7 km altitude, later dropping to the range of 4.3-6 km, with continuous emissions drifting up to 75 km WSW through the next day.
2016 Feb 6    - - - - Incandescent ejecta Strombolian explosions witnessed from the observation post in the village of Silian (about 10 km from the volcano) ejected material 300 m high.
2016 Feb 6    - - - - Lava flow PVMBG reported lava flows on the N and E flanks.
2016 Feb 6 2016 Feb 8 Thermal Anomaly Multiple near-daily MODVOLC thermal alerts were issued.
2016 Feb 6    - - - - VEI (Explosivity Index) VEI 3
2016 Feb 7    - - - - Seismicity (tremor) Constant tremor was detected.
2016 Feb 7    - - - - Ash Plume Thunderous sounds were reported, and dense ash plumes rose 2.5 km and drifted W.
2016 Feb 7    - - - - Pyroclastic flow A pyroclastic flow traveled 2 km down the E flank.
2016 Feb 7    - - - - Ashfall Ashfall was reported in multiple districts including Pasan (5 km SSE), Tombatu (16 km SSW), Belang (17 km SSE), and Ratatotok (20 km S).
2016 Feb 7    - - - - Incandescent ejecta At 0106, 0204, 0311, and 0320 Strombolian activity ejected tephra as high as 1 km above the crater.
2016 Feb 7    - - - - Audible Sounds Thunderous sounds were reported, and dense ash plumes rose 2.5 km and drifted W.
2016 Feb 9 2016 Feb 15 Degassing PVMBG reported that diffuse white plumes rose as high as 200 m above the crater.
2016 Feb 11 2016 Feb 13 Thermal Anomaly Four MODVOLC thermal alerts were issued.

2015 Jan 6 - 2015 Mar 9 Confirmed Eruption VEI: 3

Episode 1 | Eruption Summit crater and WSW flank
2015 Jan 6 - 2015 Mar 9 Evidence from Observations: Reported

List of 26 Events for Episode 1 at Summit crater and WSW flank

Start Date End Date Event Type Event Remarks
2015 Jan 6    - - - - Explosion BNPB reported that an eruption began at 1447. Based on ground reports, the Darwin VAAC reported that a significant eruption generated a plume that rose to an altitude of 8.2 km.
2015 Jan 6    - - - - Ash Plume Based on ground reports, the Darwin VAAC reported that a significant eruption generated a plume that rose to an altitude of 8.2 km. Observers at a nearby post reported a dense gray-to-black ash plume rising about 6.5 km above the summit and drifting ESE.
2015 Jan 6    - - - - Lava flow Lava flows traveled 2 km down the WSW flank.
2015 Jan 6    - - - - VEI (Explosivity Index) VEI 3
2015 Jan 7    - - - - Thermal Anomaly A MODVOLC thermal alert was issued.
2015 Jan 18    - - - - Ash Plume Based on a SIGMET, the Darwin VAAC reported that an ash plume rose to an altitude of 5.5 km. BNPB reported that an eruption at 1138 that same day generated an ash plume that rose 4 km and drifted SW.
2015 Jan 18    - - - - Incandescent ejecta Strombolian activity ejected material 500 m above the crater and incandescent avalanches of material traveled 500 m down the SW flank.
2015 Jan 18    - - - - Avalanche Strombolian activity ejected material 500 m above the crater and incandescent avalanches of material traveled 500 m down the SW flank.
2015 Jan 18    - - - - Thermal Anomaly A MODVOLC thermal alert was issued.
2015 Jan 21    - - - - Ash Plume Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that an ash plume rose to an altitude of 3.7 km and drifted over 35 km SW.
2015 Jan 21 2015 Jan 23 Thermal Anomaly Eight MODVOLC thermal alerts were issued.
2015 Feb 1 2015 Feb 3 Thermal Anomaly Five MODVOLC thermal alerts were issued.
2015 Feb 2    - - - - Ash Plume Based on statements from PVMBG, the Darwin VAAC reported that an ash plume rose to an altitude of 6.1 km. ash was not visible at the reported altitude, but possible ash was detected to the N at 3 km.
2015 Feb 2    - - - - Thermal Anomaly A thermal anomaly was visible in satellite images.
2015 Feb 6    - - - - Thermal Anomaly Two MODVOLC thermal alerts were issued.
2015 Feb 8    - - - - Ash Plume Based on satellite images and weather models, the Darwin VAAC reported that an ash plume rose to an altitude of 3 km and drifted 30 km SSE.
2015 Feb 10 2015 Feb 15 Thermal Anomaly Sixteen MODVOLC thermal alerts were issued.
2015 Feb 11 2015 Feb 12 Ash Plume Based on information from PVMBG and weather models, the Darwin VAAC reported that an eruption generated ash plumes that rose to an altitude of 3.7 km and drifted almost 30 km SE.
2015 Mar 7    - - - - Explosion Based on information from PVMBG and weather models, the Darwin VAAC reported that an eruption generated ash plumes that rose to an altitude of 9.1 km and drifted 260 km SE and SW.
2015 Mar 7    - - - - Ash Plume Based on information from PVMBG and weather models, the Darwin VAAC reported that an eruption generated ash plumes that rose to an altitude of 9.1 km and drifted 260 km SE and SW. BNPB noted that the eruption occurred at 1709, and produced ash plumes that rose 4.5 km above the crater and drifted E.
2015 Mar 7    - - - - Pyroclastic flow Pyroclastic flows traveled 2.5 km down the W flank.
2015 Mar 7    - - - - Ashfall Minor ashfall was reported in the Silian Raya district, Touluaan, Tombatu, and parts of the districts of Pasan and Rataha.
2015 Mar 7    - - - - Thermal Anomaly A thermal anomaly was detected in satellite images.
2015 Mar 7 2015 Mar 10 Thermal Anomaly Sixteen MODVOLC thermal alerts were issued.
2015 Mar 7    - - - - VEI (Explosivity Index) VEI 3
2015 Mar 8    - - - - Ash Plume The VAAC noted that an ash plume rose to an altitude of 3.7 km and drifted almost 95 km SE.

2012 Aug 26 - 2012 Sep 19 Confirmed Eruption VEI: 3

Episode 1 | Eruption Summit crater
2012 Aug 26 - 2012 Sep 19 Evidence from Observations: Reported

List of 16 Events for Episode 1 at Summit crater

Start Date End Date Event Type Event Remarks
2012 May 25    - - - - Seismicity (volcanic) Seismicity increased significantly.
2012 Aug 8 2012 Aug 23 Seismicity (volcanic) Seismicity increased during 8-22 August; on 23 August volcanic earthquakes and avalanches significantly increased.
2012 Aug 8    - - - - Observation According to NASA's Earth Observatory, a satellite image showed a small volcanic plume rising from Soputan.
2012 Aug 26    - - - - Explosion An explosion at 1936 ejected incandescent tephra 50 m above the crater and produced a plume that rose 1 km and drifted W.
2012 Aug 26    - - - - Ash Plume An explosion at 1936 ejected incandescent tephra 50 m above the crater and produced a plume that rose 1 km and drifted W.
2012 Aug 26    - - - - Incandescent ejecta An explosion at 1936 ejected incandescent tephra 50 m above the crater and produced a plume that rose 1 km and drifted W.
2012 Aug 26 2012 Aug 28 Thermal Anomaly Thirteen MODVOLC thermal alerts were issued.
2012 Aug 27    - - - - Ash Plume Based on information from CVGHM, NOAA, and analysis of satellite imagery, the Darwin VAAC reported that an ash plume rose to an altitude of 12.1 km and drifted 150 km W. The eruption lasted four hours. Later, a plume detected in satellite imagery rose to an altitude of 6.1 km.
2012 Aug 27    - - - - VEI (Explosivity Index) VEI 3
2012 Aug 28    - - - - Ash Plume An ash plume drifted 220 km SW at an altitude of 6.1 km.
2012 Sep 18    - - - - Ash Plume Based on information from US Air Force Weather Agency (AFWA), the Darwin VAAC reported that an ash plume from Soputan rose to an altitude of 9.1 km. The ash cloud dispersed to the W between the summit elevation (1,785 m) and 3.7 km altitude, and to the NNE between 3.7 and 9.1 km altitude.
2012 Sep 18 2012 Sep 19 Incandescent ejecta An eruption included an ash explosion, lava flows, and incandescent material, according to CVGHM.
2012 Sep 18 2012 Sep 19 Lava flow An eruption included an ash explosion, lava flows, and incandescent material, according to CVGHM.
2012 Sep 18 2012 Sep 22 Thermal Anomaly Multiple near-daily MODVOLC thermal alerts were issued.
2012 Sep 18    - - - - VEI (Explosivity Index) VEI 3
2012 Sep 27    - - - - Thermal Anomaly A MODVOLC thermal alert was issued.

2011 Jul 3 - 2011 Aug 15 Confirmed Eruption VEI: 3

Episode 1 | Eruption Summit crater and flank
2011 Jul 3 - 2011 Aug 15 Evidence from Observations: Reported

List of 14 Events for Episode 1 at Summit crater and flank

Start Date End Date Event Type Event Remarks
2011 Jun 21 2011 Jul 2 Seismicity (volcanic) Seismicity increased according to CVGHM.
2011 Jul 2 2011 Jul 3 Thermal Anomaly Fifteen MODVOLC thermal alerts were issued.
2011 Jul 3    - - - - Explosion A CVGHM volcanologist reported that a Strombolian eruption produced an ash plume that rose 6 km and drifted W.
2011 Jul 3    - - - - Ash Plume The Darwin VAAC reported a high-level ash plume observed in satellite imagery that extended about 400 km W from the summit at 14 km altitude. After about five hours, the high-level emission ceased but a low-level eruption continued with an ash plume drifting E at 4.6 km altitude for a few hours before dissipating later in the day.
2011 Jul 3    - - - - Ash Plume A CVGHM volcanologist reported that a Strombolian eruption produced an ash plume that rose 6 km and drifted W. Ashfall impacted villages, trees, and vegetation downwind.
2011 Jul 3    - - - - Pyroclastic flow CVGHM reported that an explosion of incandescent material was followed by a 6-km-high ash plume and a pyroclastic flow that traveled as far as 4 km W.
2011 Jul 3    - - - - Ashfall A CVGHM volcanologist reported that a Strombolian eruption produced an ash plume that rose 6 km and drifted W. Ashfall impacted villages, trees, and vegetation downwind.
2011 Jul 3    - - - - Incandescent ejecta A CVGHM volcanologist reported that a Strombolian eruption produced an ash plume that rose 6 km and drifted W.
2011 Jul 3    - - - - VEI (Explosivity Index) VEI 3
2011 Jul 9    - - - - Thermal Anomaly Two MODVOLC thermal alerts were issued.
2011 Aug 3    - - - - Thermal Anomaly A MODVOLC thermal alert was issued.
2011 Aug 14 2011 Aug 15 Thermal Anomaly Six MODVOLC thermal alerts were issued.
2011 Aug 14    - - - - Ash Plume A gray-and-white eruption plume rose 1 km above the crater. Throughout the day, two more similar plumes rose 1.3 km above the crater. Based on analysis of satellite imagery, the Darwin VAAC reported an ash plume extending about 100 km W at 3.7 km altitude.
2011 Aug 15    - - - - Lava flow An early morning photograph captured an eruption showing a small plume and lava flows down the flank of Soputan.

2008 Jun 6 - 2008 Nov 2 (?) Confirmed Eruption VEI: 3 (?)

Episode 1 | Eruption
2008 Jun 6 - 2008 Nov 2 (?) Evidence from Observations: Reported

List of 9 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
2008 Jun 6    - - - - VEI (Explosivity Index)

2007 Jun 16 (?) ± 15 days - 2007 Nov 9 (?) Confirmed Eruption VEI: 3

Episode 1 | Eruption
2007 Jun 16 (?) ± 15 days - 2007 Nov 9 (?) Evidence from Observations: Reported

List of 6 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
2007 Jun
(?)
   - - - - VEI (Explosivity Index)
2007 Oct 25    - - - - VEI (Explosivity Index)

2006 Dec 14 - 2006 Dec 26 (?) Confirmed Eruption VEI: 1

Episode 1 | Eruption
2006 Dec 14 - 2006 Dec 26 (?) Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
2006 Dec 14    - - - - VEI (Explosivity Index)

2005 Dec 26 - 2006 Jan 24 (?) Confirmed Eruption VEI: 1

Episode 1 | Eruption
2005 Dec 26 - 2006 Jan 24 (?) Evidence from Observations: Reported

List of 5 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
2005 Dec 26    - - - - VEI (Explosivity Index)

2005 Apr 19 - 2005 Jul 18 (?) Confirmed Eruption VEI: 2

Episode 1 | Eruption
2005 Apr 19 - 2005 Jul 18 (?) Evidence from Observations: Reported

List of 6 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
2005 Apr 19    - - - - VEI (Explosivity Index)

2004 Oct 18 - 2004 Dec 27 (?) Confirmed Eruption VEI: 3 (?)

Episode 1 | Eruption
2004 Oct 18 - 2004 Dec 27 (?) Evidence from Observations: Reported

List of 11 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Lightning
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
2004 Oct 18    - - - - VEI (Explosivity Index)
2004 Dec 12    - - - - VEI (Explosivity Index)

2000 May 13 - 2003 Sep 4 (?) Confirmed Eruption VEI: 2

Episode 1 | Eruption
2000 May 13 - 2003 Sep 4 (?) Evidence from Observations: Reported

List of 12 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Deformation (deflation)
   - - - -    - - - - Property Damage
2000 May 13    - - - - VEI (Explosivity Index)
2003 Jul 18    - - - - VEI (Explosivity Index)

1991 May 22 - 1996 Sep 29 (in or after) Confirmed Eruption VEI: 2

Episode 1 | Eruption
1991 May 22 - 1996 Sep 29 (in or after) Evidence from Observations: Reported

List of 10 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Earthquakes (undefined)
1991 May 22    - - - - VEI (Explosivity Index)
1995 Nov 7    - - - - VEI (Explosivity Index)
1996 Mar 15    - - - - VEI (Explosivity Index)

1989 Apr 22 - 1989 Apr 23 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1989 Apr 22 - 1989 Apr 23 Evidence from Observations: Reported

List of 7 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1989 Apr 22    - - - - VEI (Explosivity Index)

1985 May 19 - 1985 May 20 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1985 May 19 - 1985 May 20 Evidence from Observations: Reported

List of 8 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Eruption cloud
   - - - -    - - - - Ash
   - - - -    - - - - Lightning
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
1985 May 19    - - - - VEI (Explosivity Index)

1984 May 24 - 1984 Aug 31 Confirmed Eruption VEI: 3

Episode 1 | Eruption
1984 May 24 - 1984 Aug 31 Evidence from Observations: Reported

List of 10 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Eruption cloud
   - - - -    - - - - Ash
   - - - -    - - - - Bombs
   - - - -    - - - - Pumice
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1984 May 24    - - - - VEI (Explosivity Index)
1984 Aug 31    - - - - VEI (Explosivity Index)

1982 Aug 26 - 1982 Nov 10 Confirmed Eruption VEI: 3

Episode 1 | Eruption
1982 Aug 26 - 1982 Nov 10 Evidence from Observations: Reported

List of 8 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Eruption cloud
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1982 Aug 26    - - - - VEI (Explosivity Index)

1973 Jan 6 - 1973 May 27 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1973 Jan 6 - 1973 May 27 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Volcanic "smoke"
1973 Jan 6    - - - - VEI (Explosivity Index)

1971 May 19 - 1971 May 19 Confirmed Eruption VEI: 1

Episode 1 | Eruption
1971 May 19 - 1971 May 19 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity Uncertain
   - - - -    - - - - Volcanic "smoke"
1971 May 19    - - - - VEI (Explosivity Index)

1970 Feb 16 ± 15 days - 1970 May 26 ± 5 days Confirmed Eruption VEI: 2

Episode 1 | Eruption
1970 Feb 16 ± 15 days - 1970 May 26 ± 5 days Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Audible Sounds
1970 Feb    - - - - VEI (Explosivity Index)

1968 Jul 16 ± 15 days - 1968 Aug 16 ± 15 days Confirmed Eruption VEI: 1

Episode 1 | Eruption
1968 Jul 16 ± 15 days - 1968 Aug 16 ± 15 days Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Pyroclastic flow weak or small
   - - - -    - - - - Lava dome
   - - - -    - - - - Earthquakes (undefined)
1968 Jul    - - - - VEI (Explosivity Index)

1966 May 21 - 1967 Nov 16 ± 15 days Confirmed Eruption VEI: 3

Episode 1 | Eruption Kawah Soputan
1966 May 21 - 1967 Nov 16 ± 15 days Evidence from Observations: Reported

List of 9 Events for Episode 1 at Kawah Soputan

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion moderate
   - - - -    - - - - Eruption cloud
   - - - -    - - - - Pyroclastic flow weak or small
   - - - -    - - - - Lava flow weak or small
   - - - -    - - - - Lava dome
   - - - -    - - - - Lahar or Mudflow
   - - - -    - - - - Property Damage
1966 May 21    - - - - VEI (Explosivity Index)
1967 Mar 11    - - - - VEI (Explosivity Index)

1953 Nov 16 ± 15 days Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1953 Nov 16 ± 15 days - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion Uncertain
1953 Nov    - - - - VEI (Explosivity Index)

1947 Aug 22 - 1947 Aug 27 Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1947 Aug 22 - 1947 Aug 27 Evidence from Observations: Reported

List of 2 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1947 Aug 22    - - - - VEI (Explosivity Index)

1923 Nov 27 - 1924 Jan 18 Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1923 Nov 27 - 1924 Jan 18 Evidence from Observations: Reported

List of 6 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash
   - - - -    - - - - Bombs
1923 Nov 27    - - - - VEI (Explosivity Index)
1924 Jan 14    - - - - VEI (Explosivity Index)

1917 Nov Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1917 Nov - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1917 Nov    - - - - VEI (Explosivity Index)

1915 Apr - 1915 Jun Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput Weru)
1915 Apr - 1915 Jun Evidence from Observations: Reported

List of 3 Events for Episode 1 at NE flank (Aeseput Weru)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava dome
1915 Apr    - - - - VEI (Explosivity Index)

1913 Apr - 1913 Jul Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1913 Apr - 1913 Jul Evidence from Observations: Reported

List of 2 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1913 Apr    - - - - VEI (Explosivity Index)

1911 Nov - 1912 Apr Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1911 Nov - 1912 Apr Evidence from Observations: Reported

List of 3 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
1911 Nov    - - - - VEI (Explosivity Index)

1910 Nov 15 ± 45 days Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1910 Nov 15 ± 45 days - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
1910 Nov 15 ± 45 days    - - - - VEI (Explosivity Index)

1908 Jun - 1909 Jun Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1908 Jun - 1909 Jun Evidence from Observations: Reported

List of 3 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
1908 Jun    - - - - VEI (Explosivity Index)

1907 Jun 5 - 1907 Jun 25 (?) Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1907 Jun 5 - 1907 Jun 25 (?) Evidence from Observations: Reported

List of 3 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Earthquakes (undefined)
1907 Jun 5    - - - - VEI (Explosivity Index)

1906 Jun 17 - 1906 Sep Confirmed Eruption VEI: 2

Episode 1 | Eruption NE flank (Aeseput)
1906 Jun 17 - 1906 Sep Evidence from Observations: Reported

List of 4 Events for Episode 1 at NE flank (Aeseput)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Crater Parasitic.
1906 Jun 17    - - - - VEI (Explosivity Index)

1901 Feb 4 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1901 Feb 4 - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Earthquakes (undefined) Before.
1901 Feb 4    - - - - VEI (Explosivity Index)

1890 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1890 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion Uncertain
1890    - - - - VEI (Explosivity Index)

1845 Feb 8 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1845 Feb 8 - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Tsunami
1845 Feb 8    - - - - VEI (Explosivity Index)

1833 (?) Confirmed Eruption VEI: 2

Episode 1 | Eruption
1833 (?) - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1833
(?)
   - - - - VEI (Explosivity Index)

1819 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1819 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1819    - - - - VEI (Explosivity Index)

1785 Dec 31 ± 365 days Confirmed Eruption VEI: 2

Episode 1 | Eruption
1785 Dec 31 ± 365 days - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1785 Dec 31 ± 365 days    - - - - VEI (Explosivity Index)

1450 ± 10 years Confirmed Eruption VEI: 3

Episode 1 | Eruption
1450 ± 10 years - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1450 ± 10 years    - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Soputan.

Emission History

There is data available for 22 emission periods. Expand each entry for additional details.


Emissions during 2016 Jan 05 - 2016 Jan 05 [3 kt SO2 at 12 km altitude]

Start Date: 2016 Jan 05 Stop Date: 2016 Jan 05 Method: Satellite (Aura OMI)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 3 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20160105 11.8 3.000

Emissions during 2016 Feb 06 - 2016 Feb 06 [5 kt SO2 at 7 km altitude]

Start Date: 2016 Feb 06 Stop Date: 2016 Feb 06 Method: Satellite (Aura OMI)
SO2 Altitude Min: 7 km SO2 Altitude Max: 7 km Total SO2 Mass: 5 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20160206 7.0 5.000

Emissions during 2015 Feb 02 - 2015 Feb 02 [2 kt SO2 at 6 km altitude]

Start Date: 2015 Feb 02 Stop Date: 2015 Feb 02 Method: Satellite (Aura OMI)
SO2 Altitude Min: 6 km SO2 Altitude Max: 6 km Total SO2 Mass: 2 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20150202 6.0 2.000

Emissions during 2012 Sep 18 - 2012 Sep 18 [10 kt SO2 at 9 km altitude]

Start Date: 2012 Sep 18 Stop Date: 2012 Sep 18 Method: Satellite (Aura OMI)
SO2 Altitude Min: 9 km SO2 Altitude Max: 9 km Total SO2 Mass: 10 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20120918 9.0 10.000

Emissions during 2012 Aug 27 - 2012 Aug 27 [2 kt SO2 at 12 km altitude]

Start Date: 2012 Aug 27 Stop Date: 2012 Aug 27 Method: Satellite (Aura OMI)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 2 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20120827 12.0 2.000

Emissions during 2011 Jul 03 - 2011 Jul 03 [10 kt SO2 at 14 km altitude]

Start Date: 2011 Jul 03 Stop Date: 2011 Jul 03 Method: Satellite (Aura OMI)
SO2 Altitude Min: 14 km SO2 Altitude Max: 14 km Total SO2 Mass: 10 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20110703 14.0 10.000

Emissions during 2011 Aug 14 - 2011 Aug 14 [2 kt SO2 at 4 km altitude]

Start Date: 2011 Aug 14 Stop Date: 2011 Aug 14 Method: Satellite (Aura OMI)
SO2 Altitude Min: 4 km SO2 Altitude Max: 4 km Total SO2 Mass: 2 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20110814 4.0 2.000

Emissions during 2008 Oct 06 - 2008 Oct 06 [16 kt SO2 at 8 km altitude]

Start Date: 2008 Oct 06 Stop Date: 2008 Oct 06 Method: Satellite (Aura OMI)
SO2 Altitude Min: 8 km SO2 Altitude Max: 8 km Total SO2 Mass: 16 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20081006 8.0 16.000

Emissions during 2008 Jun 06 - 2008 Jun 06 [33 kt SO2 at 14 km altitude]

Start Date: 2008 Jun 06 Stop Date: 2008 Jun 06 Method: Satellite (Aura OMI)
SO2 Altitude Min: 14 km SO2 Altitude Max: 14 km Total SO2 Mass: 33 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20080606 14.0 33.000

Emissions during 2007 Oct 25 - 2007 Oct 25 [12 kt SO2 at 14 km altitude]

Start Date: 2007 Oct 25 Stop Date: 2007 Oct 25 Method: Satellite (Aura OMI)
SO2 Altitude Min: 14 km SO2 Altitude Max: 14 km Total SO2 Mass: 12 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20071025 14.0 12.000

Emissions during 2007 Aug 14 - 2007 Aug 14 [5 kt SO2 at 3 km altitude]

Start Date: 2007 Aug 14 Stop Date: 2007 Aug 14 Method: Satellite (Aura OMI)
SO2 Altitude Min: 3 km SO2 Altitude Max: 3 km Total SO2 Mass: 5 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20070814 3.0 5.000

Emissions during 2006 Dec 14 - 2006 Dec 14 [10 kt SO2 at 12 km altitude]

Start Date: 2006 Dec 14 Stop Date: 2006 Dec 14 Method: Satellite (Aura OMI)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 10 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20061214 12.0 10.000

Emissions during 2005 Dec 27 - 2005 Dec 27 [5 kt SO2 at 6 km altitude]

Start Date: 2005 Dec 27 Stop Date: 2005 Dec 27 Method: Satellite (Aura OMI)
SO2 Altitude Min: 6 km SO2 Altitude Max: 6 km Total SO2 Mass: 5 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20051227 6.0 5.000

Emissions during 2005 Apr 20 - 2005 Apr 20 [2 kt SO2 at 3 km altitude]

Start Date: 2005 Apr 20 Stop Date: 2005 Apr 20 Method: Satellite (Aura OMI)
SO2 Altitude Min: 3 km SO2 Altitude Max: 3 km Total SO2 Mass: 2 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20050420 3.0 1.500

Emissions during 2004 Oct 18 - 2004 Oct 18 [10 kt SO2 at 12 km altitude]

Start Date: 2004 Oct 18 Stop Date: 2004 Oct 18 Method: Satellite (Aura OMI)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 10 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20041018 11.8 10.000

Emissions during 2004 Dec 13 - 2004 Dec 13 [15 kt SO2 at 11 km altitude]

Start Date: 2004 Dec 13 Stop Date: 2004 Dec 13 Method: Satellite (Aura OMI)
SO2 Altitude Min: 11 km SO2 Altitude Max: 11 km Total SO2 Mass: 15 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20041213 11.0 15.000

Emissions during 2003 Sep 01 - 2003 Sep 01 [16 kt SO2 at 12 km altitude]

Start Date: 2003 Sep 01 Stop Date: 2003 Sep 01 Method: Satellite (Earth Probe TOMS)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 16 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20030901 11.8 16.000

Emissions during 1985 May 20 - 1985 May 20 [12 kt SO2 at 12 km altitude]

Start Date: 1985 May 20 Stop Date: 1985 May 20 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 12 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850520 11.8 12.000

Emissions during 1984 May 24 - 1984 May 24 [166 kt SO2 at 16 km altitude]

Start Date: 1984 May 24 Stop Date: 1984 May 24 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 16 km SO2 Altitude Max: 16 km Total SO2 Mass: 166 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840524 16.0 166.000

Emissions during 1984 Aug 31 - 1984 Aug 31 [26 kt SO2 at 12 km altitude]

Start Date: 1984 Aug 31 Stop Date: 1984 Aug 31 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 26 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840831 11.8 26.000

Emissions during 1982 Nov 10 - 1982 Nov 10 [13 kt SO2 at 12 km altitude]

Start Date: 1982 Nov 10 Stop Date: 1982 Nov 10 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 12 km SO2 Altitude Max: 12 km Total SO2 Mass: 13 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19821110 11.8 13.000

Emissions during 1982 Aug 27 - 1982 Aug 27 [90 kt SO2 at 15 km altitude]

Start Date: 1982 Aug 27 Stop Date: 1982 Aug 27 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 15 km SO2 Altitude Max: 15 km Total SO2 Mass: 90 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19820827 15.0 90.000
Photo Gallery

Soputan volcano, a small 580-m-high stratovolcano, seen here from Bukit Keledondei on the NE side, is a youthful, largely unvegetated volcano with a prominent flank cone, Aeseput, visible here in the center of the photo. Soputan is one of Sulawesi's most active volcanoes; both it and Aeseput, which was formed in 1906, have erupted frequently since the 18th century.

Photo by Ruska Hadian, 1973 (Volcanological Survey of Indonesia).
During an eruption in 1966-67, a lava dome was emplaced at the summit of Soputan, and a lava flow, seen steaming here in 1973, descended its flanks. The eruption began with a vulcanian explosion on May 21, and lava outflow began June 12-15, resumed again in November and continued until November of the following year.

Photo by Ruska Hadian, 1973 (Volcanological Survey of Indonesia).
During an eruption in 1966-67, a lava dome was emplaced at the summit of Soputan. A blocky lava flow, seen here steaming along the right-hand skyline from the NE-flank cone of Aeseput, descended its flanks. The eruption began with a vulcanian explosion on May 21, and lava outflow began June 12-15, resumed again in November, and continued until November of the following year. An explosive eruption accompanied by pyroclastic flows took place on September 25, 1966.

Photo by Ruska Hadian, 1973 (Volcanological Survey of Indonesia).
The broad 1549-m-high Sempu stratovolcano (background) is seen here from the summit of neighboring Soputan volcano. The prominent cone in the center is Aeseput, a 20th-century cone constructed on the NW flank of Soputan. Gunung Sempu volcano was constructed within a 3-km-wide caldera. Kawah Masem maar was formed in the SW part of the caldera and contains a crater lake and fumarolic areas that have been the site of sulfur extraction. No historical eruptions are known from Sempu.

Photo by Ruska Hadian, 1973 (Volcanological Survey of Indonesia).
An eruption plume, viewed from the north, rises from the summit of Soputan volcano on September 13, 1982. The eruption began on August 26, when an eruption column rose 15 km, and lasted until November 10. The August 26 explosion prompted the evacuation of 850 inhabitants of a village on the flank of the volcano.

Photo by Ruska Hadian, 1982 (Volcanological Survey of Indonesia).
The small conical volcano of Soputan on the southern rim of the Quaternary Tondano caldera is one of Sulawesi's most active volcanoes. Gunung Soputan is seen here in profile from the east. During historical time eruptions have originated both from the summit crater and Aeseput (extreme right), a prominent NE flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Photo by Willem Rohi, 1988 (Volcanological Survey of Indonesia).
The small Soputan stratovolcano, seen here from the west, was constructed on the southern rim of the Quaternary Tondano caldera in northern Sulawesi Island. The youthful, largely unvegetated Soputan volcano is one of Sulawesi's most active volcanoes. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Photo by Agus Solihin (Volcanological Survey of Indonesia).
A pyroclastic flow produced by collapse of a growing lava dome descends the flank of Soputan on July 18, 2005. Soputan erupted on April 20, 2005, with a plume reaching ~ 1 km above the summit and lava fountains rising ~ 200 m above the volcano. MODIS thermal alerts had begun the night of the 19th. Rapid lava dome growth occurred in April, and by 21st the lava dome had spread about 250 m E and 200 m SW.

Photo by Farid Bina, 2005 ( Directorate of Volcanology and Geological Hazard Mitigation).
GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

There are no samples for Soputan in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites