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Dempo

Photo of this volcano
  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 4.016°S
  • 103.121°E

  • 3,142 m
    10,308 ft

  • 261230
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 20 November-26 November 2024 Citation IconCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dempo was recorded at 1338 on 23 November. Jets of dark material were ejected around 200 m above the lake’s surface, mainly to the N. The eruption lasted about four minutes based on the seismic data. According to a news article, there were 68 registered climbers on Dempo when the eruption occurred, though no one was near the summit at the time; the volcano was closed to climbers on 24 November. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Antara News


Most Recent Bulletin Report: September 2023 (BGVN 48:09) Citation IconCite this Report

Weak explosions, some with ash, from the crater lake during July and August 2023

The Dempo stratovolcano in SE Sumatra, Indonesia, has had many small explosions reported since 1817. The active crater contains a 400-m-wide lake was the source of phreatic explosions in 2006, 2009, 2017, and most recently in May 2022. This report covers activity from June 2022 to December 2023, based on daily and special reports of the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), and satellite data. Throughout the reporting period, the Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

PVMBG reported that at 2115 on 25 July 2023, an explosion produced a white-and-gray ash plume that rose at least 2 km above the summit and drifted S and SW. Additional ash explosions were recorded at 1547 and 2215 on 26 July, the latter rising 2 km above the summit crater and drifting S and SW, based on ground observations. Another explosion was reported by PVMBG at 2105 on 21 August, but no ash emissions were observed. Webcam images posted in daily MAGMA Indonesia reports showed possible patches of discolored water or material floating on the surface of the crater lake during 27-29 August (figure 8).

Figure (see Caption) Figure 8. Webcam image of Dempo’s crater lake on 29 August 2023, showing material floating on surface. Courtesy of MAGMA Indonesia.

Most Sentinel-2 satellite views of Dempo during the reporting period were obscured by weather clouds. When observations were possible, the crater lake surface typically looked milky gray, indicating high levels of particulate matter. However, during several days in March and April 2023 the lake took on a blue appearance.

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.esdm.go.id/v1); Copernicus Browser (URL: https://dataspace.copernicus.eu/browser).

Weekly Reports - Index


2024: May | August | November
2023: July | August
2022: May
2017: April | November
2015: April | September
2009: March
2008: December
2006: September


20 November-26 November 2024 Citation IconCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dempo was recorded at 1338 on 23 November. Jets of dark material were ejected around 200 m above the lake’s surface, mainly to the N. The eruption lasted about four minutes based on the seismic data. According to a news article, there were 68 registered climbers on Dempo when the eruption occurred, though no one was near the summit at the time; the volcano was closed to climbers on 24 November. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


7 August-13 August 2024 Citation IconCite this Report

According to a news article the public was reminded to stay 1 km away from Dempo’s main crater and as far as 2 km on the N flank because of potential eruptions and toxic gases. The crater lake was turquoise green on 5 August and gray on 8 August. The Alert Level remained at 2 (on a scale of 1-4).

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


29 May-4 June 2024 Citation IconCite this Report

PVMBG reported that at 0358 on 31 May an eruption at Dempo generated a whitish ash plume that rose around 200 m above the crater rim and drifted N. The eruption lasted about 39 seconds based on seismic data. According to a news article, Dempo was closed to climbers for a week starting on 2 June. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


22 May-28 May 2024 Citation IconCite this Report

PVMBG reported that an eruption at Dempo occurred at 0406 on 27 May. A video posted with the report showed a Surtseyan eruption at the crater lake with dark material being ejected 300 m from the center of the lake. Dense white-and-gray ash plumes rose around 500 m and drifted W. According to a news report, the crater lake water had been changing colors during the previous few weeks. The color changed from turquois-green to gray and white on 9 May, and a diffuse gas-and-steam plume was visible. A seismic signal indicating an emission was recorded at 1911 on 12 May. The water turned turquois-green again on 15 May and then to gray on 17 May. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


23 August-29 August 2023 Citation IconCite this Report

Webcam images of Dempo posted in the daily PVMBG reports showed possible patches of discolored water or material floating on the surface of the crater lake during 27-29 August. The Aviation Color Code was raised to Orange (the third color on a four-color scale). The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


16 August-22 August 2023 Citation IconCite this Report

PVMBG reported that an eruption at Dempo occurred at 2105 on 21 August, but no ash emissions were observed. A video posted on social media showed a Surtseyan eruption through the crater lake, with steam plumes and dark material being ejected above the lake. The Aviation Color Code was raised to Orange (the third color on a four-color scale). The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM); Tribun Sumsel


26 July-1 August 2023 Citation IconCite this Report

PVMBG reported that the eruption at Dempo continued during 26 July-1 August. An ash plume at 2215 on 26 July rose 2 km (6,400 ft) above the summit crater and drifted S and SW, based on ground observations. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


19 July-25 July 2023 Citation IconCite this Report

PVMBG reported that at 2115 on 25 July an eruption at Dempo produced a white-and-gray ash plume that rose at least 2 km above the summit and drifted S and SW. An eruptive event was recorded at 1547 on 26 July but weather conditions prevented views of the volcano. At 2115 PVMBG issued a Volcano Observatory Notice for Aviation (VONA) stating that activity was increasing. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


25 May-31 May 2022 Citation IconCite this Report

PVMBG reported that at 0154 on 31 May a phreatic eruption at Dempo produced ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District. Ash deposits were as thick as 1 mm. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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


8 November-14 November 2017 Citation IconCite this Report

According to PVMBG a three-minute-long phreatic eruption at Dempo began at 1651 on 9 November, and generated a dense ash plume that rose 4.2 km (13,800 ft) a.s.l., about 1 km above the crater rim, and drifted S. The Alert Level remained at 2 (on a scale of 1-4).

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


5 April-11 April 2017 Citation IconCite this Report

Observers at the PVMBG Dempo observation post reported that during January and February no plumes rose from Dempo's crater, and during 1 March-4 April diffuse white plumes rose no higher than 50 m above the crater. Seismicity increased from 21 March to 4 April. The Alert Level was raised to 2 (on a scale from 1-4) on 5 April. Visitors and residents were advised not to approach the craters within 3 km.

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


9 September-15 September 2015 Citation IconCite this Report

Observers at the PVMBG Dempo observation post reported that during 1 June-9 September no plumes rose from Dempo's crater and seismicity was low. On 10 September the Alert Level was lowered to 1 (on a scale from 1-4). Visitors and residents were advised not to approach the craters.

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


29 April-5 May 2015 Citation IconCite this Report

Observers at the PVMBG Dempo observation post reported that during 0730-0900 on 27 April diffuse gray-white plumes rose 50 m above Dempo crater. Seismicity had increased during April as compared to the previous month. On 29 April the Alert Level was raised to 2 (on a scale from 1-4). Visitors and residents were advised not to go within a 1-km radius of the summit.

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


18 March-24 March 2009 Citation IconCite this Report

On 23 March, CVGHM lowered the Alert Level for Dempo from 2 to 1 (on a scale of 1-4) based on visual observations of the crater lake during 5-6 January and 2-4 March, and decreased seismicity since a phreatic eruption on 1 January. Visitors and residents were advised not to go within a 1-km radius of the summit.

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


31 December-6 January 2009 Citation IconCite this Report

CVGHM reported that on 1 January, a phreatic eruption from Dempo resulted in a strong sulfur odor and "ash rain" that was noted as far as about 10 km from the summit. Fog prevented direct observations of the summit. The Alert Level was raised to 2 (on a scale from 1-4). Visitors and residents were advised not to go within a 2-km radius of the summit.

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


20 September-26 September 2006 Citation IconCite this Report

Increased seismicity at Dempo resulted in an elevation of the hazard status to Alert Level 2.

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


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.

08/1999 (BGVN 24:08) Earthquakes 18-19 September increase alert status

01/2009 (BGVN 34:01) Sudden phreatic eruption on 1 January 2009

03/2009 (BGVN 34:03) Phreatic eruption in September 2006 sent mud 300 m

12/2017 (BGVN 42:12) Phreatic explosion from the crater lake generates a dense ash plume in November 2017

06/2022 (BGVN 47:06) Phreatic explosion on 31 May 2022

09/2023 (BGVN 48:09) Weak explosions, some with ash, from the crater lake during July and August 2023




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


August 1999 (BGVN 24:08) Citation IconCite this Report

Earthquakes 18-19 September increase alert status

At 1810 on 18 September an earthquake was felt in an area around Dempo. The Volcanological Survey of Indonesia (VSI) reported its Modified Mercalli (MM) Intensity as MM IV. The following day three more earthquakes were felt: the first event took place at 0900 (MM II), the next at 1155 (MM I), and the last at 1800 (MM I). Recorded seismicity during these days indicated 30 events/day with amplitudes of 20-30 mm and arrival time differences (S-P) of 2-3 seconds on average. Volcanologists took this to mean that the earthquakes were local tectonic events. No visible signs of changed activity were apparent at the crater. The VSI took the precaution of increasing the condition of alert to Level II.

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


January 2009 (BGVN 34:01) Citation IconCite this Report

Sudden phreatic eruption on 1 January 2009

According to a report by Indonesia's Center of Volcanology and Geological Hazard Mitigation (CVGHM), Dempo had a phreatic eruption on 1 January 2009. The event resulted in a strong sulfur odor and an ash (or cinder) rain that was noted as far as ~ 10 km from the summit. During 27 December 2008 to 1 January 2009, fog prevented direct observations of the summit; clouds over the summit area are a common occurrence. The one available photo of the eruption showed a whitish-colored plume rising perhaps a few kilometers over the summit.

On 1 January authorities raised the alert status from 1 (normal) to 2 (alert, "Waspada" in Indonesian), on a scale that ranges from 1-4. Visitors and residents were advised not to go within a 2-km radius of the summit. A 2 January report from CVGHM noted that both local volcanic and regional tectonic earthquakes were recorded during 27 December 2008 through 1 January 2009 (table 1).

Table 1. Highlights of Dempo seismicity recorded during 27 December 2008 to 1 January 2009. Courtesy of CVGHM.

Date Seismicity
27 Dec 2008 One local volcanic (A-type), and two tectonic.
28 Dec 2008 One local volcanic (A-type), and one air blast event.
29 Dec 2008 One local volcanic, five air blasts, and two tectonic.
30 Dec 2008 One shallow local volcanic, one air blast, one low-frequency, and one tectonic.
31 Dec 2008 One local volcanic, one air blast, and two tectonic not at the volcano.
01 Jan 2009 One local volcanic related to the explosive eruption.

As of early 2009, no thermal anomalies had been measured over Dempo by the MODVOLC infrared satellite system for at least the last 5 years. ASTER images from 2001-2007 show extensive cloud cover.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/); 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/).


March 2009 (BGVN 34:03) Citation IconCite this Report

Phreatic eruption in September 2006 sent mud 300 m

Our most recent report on Dempo (BGVN 34:01) discussed a phreatic eruption on 1 January 2009. This eruption prompted Indonesia's Center of Volcanology and Geological Hazard Mitigation (CVGHM) to raise the alert level from 1 (normal) to 2 (alert) on a scale of 1-4. A few months later, on 23 March 2009, the CVGHM lowered Dempo's Alert Level to 1, based on visual observations of the crater lake during 5-6 January and 2-4 March, and decreased seismicity since the 1 January phreatic eruption.

The name Dempo applies to both the larger complex and to a peak that sits adjacent to a neighboring peak called Marapi. The latter volcano name applies to several different volcanoes in Indonesia and is easily confused with the very prominent volcano Merapi (central Java). The Marapi cone in the Dempo complex contains a ~ 400 m diameter crater lake, the source of both the 2006 and 2009 eruptions.

The remainder of this report discusses the phreatic eruption that occurred in September 2006. This eruption had not been previously discussed in the Bulletin, and CVGHM reporting on the subject has recently come to our attention.

In the month before this eruption, teams from the CVGHM had visited several times. On 13 August 2006, a team prepared a map of Dempo and reported that the condition of the water in Marapi's crater lake was normal and clear or slightly blue in color, with no bubbling. On 4 September 2006, a team climbed to the peak of Dempo and reported that activity was normal other than some bubbling at the E edge of the crater lake.

2006 phreatic eruption. On 25 September 2006, a phreatic eruption occurred that expelled water from Marapi's crater lake and propelled mud onto the area around the peak up to a radius of 300 m.

On the next day, the inspector for Dempo, Mr. Mulyadi, accompanied by six friends, inspected the volcano and its lake. According to Mulyadi's team, the lake water was bubbling and had changed to a grayish color. Acrid sulfurous emissions were accompanied by a hissing sound. The NW crater wall was covered by mud from the eruption. Many of the phreatic deposits around the crater lake were only about 0.5 cm thick, although in several other places they were thicker (figures 1-4). A visit on 4 October 2006 found the deposits not yet eroded, owing to a lack of rain since the eruption.

Figure (see Caption) Figure 1. Photo of the plume resulting from Dempo's phreatic eruption on 25 September 2006. This is one of a set of multiple photos taken of a rising plume. Photo by Fredy, a local resident. Courtesy of CVGHM.
Figure (see Caption) Figure 2. (top) Pre-eruption and (bottom) post-eruption scenes from the saddle between the cones of Dempo and Marapi looking upslope towards Marapi (which contains the source vent in a steep-sided crater not visible from this perspective). The shots were taken on 7 and 26 September 2009, respectively. Freshly deposited mud and evidence of ejected crater-lake water in the foreground (bottom) represents distal deposits from the 25 September eruption; note peson at right for scale. Large blocks were not from this eruption. Courtesy of the Dempo inspection team, CVGHM.
Figure (see Caption) Figure 3. Pre- and post-eruption photos looking into Marapi crater at Dempo, taken on 7 (top) and 26 (bottom) September 2006. The lake is on the order of 400 m across. The bottom photo portrays the crater's mud-covered walls and sediment-covered lake. Comparison of both photos indicates that after the eruption the lake surface had dropped, consistent with discharge of water and mud. Camera look-direction unstated. Courtesy of the Dempo inspection team, CVGHM.
Figure (see Caption) Figure 4. Post-eruption conditions on Dempo's Marapi cone seen from a point a few meters back from the crater rim. Widespread gray-to-brown mud covered the rim and upper crater, creating a desolate scene. The large angular blocks on the rim were placed there in previous events, not the 25 September 2009 eruption. Unstated direction; photographers shadow and gear for scale. Courtesy of the Dempo inspection team, CVGHM.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/).


December 2017 (BGVN 42:12) Citation IconCite this Report

Phreatic explosion from the crater lake generates a dense ash plume in November 2017

Activity at Dempo on Sumatra in recent years has consisted of brief phreatic eruptions, most recently single-day events on 25 September 2006 (BGVN 34:03) and 1 January 2009 (BGVN 34:01). There were no additional reports from the Center of Volcanology and Geological Hazard Mitigation (CVGHM), also known as Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), until a brief episode of unrest in late April 2015, Another typically short phreatic explosion took place on 9 November 2017.

Activity during 2015. On 29 April the Alert Level was raised to 2 (on a scale of 1-4) by PVMBG following observations of diffuse white-gray plumes on 27 April rising to 50 m above the crater. Seismicity had increased during April compared to the previous month (figure 5). A Detik news report on 30 April quoted the PVMBG Head of the Western Volcano Field of Observation and Investigation, Hendra Gunawan, as saying that there had been tremor recorded over the previous four days. No ashfall was reported by PVMBG, and a phreatic eruption was only mentioned in the 29 April notice as a potential danger.

Figure (see Caption) Figure 5. Seismicity recorded at Dempo from 1 January to 29 April 2015. The types of earthquakes reported are HBS (Hembusan, puff or emission events), Trm (tremor), VB (shallow volcanic type B), VA (volcanic type A), TL (local tectonic), and TJ (distant tectonic). Courtesy of PVMBG.

Observers reported that during 1 June-9 September 2015 no plumes were seen and seismicity was low. On 10 September PVMBG lowered the Alert Level to 1.

Activity during 2017. Staff at the PVMBG Dempo observation post reported that no plumes rose from the crater during January and February 2017, but some diffuse white plumes during 1 March-4 April rose no higher than 50 m. Seismicity increased significantly above background levels from 21 March to 4 April (figure 5). On 5 April PVMBG raised the Alert Level to 2 based on visual and seismic data, but did not report any phreatic eruptions.

Figure (see Caption) Figure 6. Seismicity recorded at Dempo from 31 December 2016 to 6 April 2017. The types of earthquakes reported are HBS (Hembusan, puff or emission events), TRE (tremor), VB (shallow volcanic type B), VA (volcanic type A), TL (local tectonic), and TJ (distant tectonic). Courtesy of PVMBG.

According to PVMBG a three-minute-long phreatic eruption began at 1651 on 9 November 2017 and generated a dense ash plume that rose to 4.2 km altitude, about 1 km above the crater rim, and drifted S. Ashfall and sulfur gases were reported in villages on the S flanks, but there was no damage to property or injuries. The Alert Level remained at 2, with a 3-km-diameter exclusion zone; the Aviation Color Code was at Yellow.

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/); Detiknews (URL: https://news.detik.com/).


June 2022 (BGVN 47:06) Citation IconCite this Report

Phreatic explosion on 31 May 2022

The Dempo stratovolcano in SE Sumatra, Indonesia, has had many small explosive eruptions reported since 1817. The active Marapi crater (750 x 1,100 m) in the summit area contains a 400-m-wide crater lake (figure 7). Recent activity has consisted of single-day phreatic explosions in September 2006, January 2009, and November 2017. Indonesian’s Center of Volcanology and Geological Hazard Mitigation (CVGHM), also known as Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), is the monitoring agency.

Figure (see Caption) Figure 7. Satellite image of Dempo on 30 May 2022, showing the 400-m-wide crater lake within the Marapi summit crater. Sentinel-2 image with natural color rendering (bands 4, 3, 2). Courtesy of Sentinel Hub Playground.

PVMBG reported phreatic explosion similar to those of recent years at 0154 on 31 May 2022. This event lasted 239 seconds and produced ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District; ash deposits were as thick as 1 mm. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


September 2023 (BGVN 48:09) Citation IconCite this Report

Weak explosions, some with ash, from the crater lake during July and August 2023

The Dempo stratovolcano in SE Sumatra, Indonesia, has had many small explosions reported since 1817. The active crater contains a 400-m-wide lake was the source of phreatic explosions in 2006, 2009, 2017, and most recently in May 2022. This report covers activity from June 2022 to December 2023, based on daily and special reports of the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), and satellite data. Throughout the reporting period, the Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.

PVMBG reported that at 2115 on 25 July 2023, an explosion produced a white-and-gray ash plume that rose at least 2 km above the summit and drifted S and SW. Additional ash explosions were recorded at 1547 and 2215 on 26 July, the latter rising 2 km above the summit crater and drifting S and SW, based on ground observations. Another explosion was reported by PVMBG at 2105 on 21 August, but no ash emissions were observed. Webcam images posted in daily MAGMA Indonesia reports showed possible patches of discolored water or material floating on the surface of the crater lake during 27-29 August (figure 8).

Figure (see Caption) Figure 8. Webcam image of Dempo’s crater lake on 29 August 2023, showing material floating on surface. Courtesy of MAGMA Indonesia.

Most Sentinel-2 satellite views of Dempo during the reporting period were obscured by weather clouds. When observations were possible, the crater lake surface typically looked milky gray, indicating high levels of particulate matter. However, during several days in March and April 2023 the lake took on a blue appearance.

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.esdm.go.id/v1); Copernicus Browser (URL: https://dataspace.copernicus.eu/browser).

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 31 confirmed Holocene eruptive periods.

2024 May 27 - 2024 May 31 Confirmed Eruption VEI: 1

Episode 1 | Eruption
2024 May 27 - 2024 May 31 Evidence from Observations: Reported

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
2024 May 27    - - - - VEI (Explosivity Index) VEI 1

2023 Jul 25 - 2023 Aug 21 Confirmed Eruption VEI: 2

Episode 1 | Eruption
2023 Jul 25 - 2023 Aug 21 Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
2023 Jul 26    - - - - Ash Plume An ash plume at 2215 on 26 July rose 2 km above the summit.
2023 Jul 26    - - - - VEI (Explosivity Index) VEI 2

2022 May 31 - 2022 May 31 Confirmed Eruption VEI: 1

Episode 1 | Eruption (Phreatic)
2022 May 31 - 2022 May 31 Evidence from Observations: Reported
 Phreatic explosion similar to those of recent years at 0154 on 31 May 2022. This event lasted 239 seconds and produced ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District; ash deposits were as thick as 1 mm.

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
2022 May 31    - - - - Phreatic activity
2022 May 31    - - - - Ashfall Ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District; ash deposits were as thick as 1 mm.
2022 May 31    - - - - VEI (Explosivity Index) VEI 1

2017 Nov 9 - 2017 Nov 9 Confirmed Eruption VEI: 1

Episode 1 | Eruption Summit crater
2017 Nov 9 - 2017 Nov 9 Evidence from Observations: Reported

List of 5 Events for Episode 1 at Summit crater

Start Date End Date Event Type Event Remarks
2017 Nov 9    - - - - Explosion According to PVMBG a three-minute-long phreatic eruption began at 1651 and generated a dense ash plume that rose to 4.2 km altitude, about 1 km above the crater rim, and drifted S.
2017 Nov 9    - - - - Phreatic activity According to PVMBG a three-minute-long phreatic eruption began at 1651 and generated a dense ash plume that rose to 4.2 km altitude, about 1 km above the crater rim, and drifted S.
2017 Nov 9    - - - - Ash Plume According to PVMBG a three-minute-long phreatic eruption began at 1651 and generated a dense ash plume that rose to 4.2 km altitude, about 1 km above the crater rim, and drifted S.
2017 Nov 9    - - - - Ashfall According to PVMBG ashfall and sulfur gases were reported in villages on the S flanks, but there was no damage to property or injuries.
2017 Nov 9    - - - - VEI (Explosivity Index) VEI 1

2009 Jan 1 - 2009 Jan 1 Confirmed Eruption VEI: 1 (?)

Episode 1 | Eruption
2009 Jan 1 - 2009 Jan 1 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
2009 Jan 1    - - - - VEI (Explosivity Index)

2006 Sep 25 - 2006 Sep 25 Confirmed Eruption VEI: 1

Episode 1 | Eruption
2006 Sep 25 - 2006 Sep 25 Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
2006 Sep 25    - - - - VEI (Explosivity Index)

1994 Oct 16 ± 15 days - 1994 Oct 16 ± 15 days Confirmed Eruption VEI: 1

Episode 1 | Eruption
1994 Oct 16 ± 15 days - 1994 Oct 16 ± 15 days Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash weak or small
1994 Oct    - - - - VEI (Explosivity Index)

1974 Feb 26 - 1974 Oct 20 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1974 Feb 26 - 1974 Oct 20 Evidence from Observations: Reported

List of 6 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion Uncertain
   - - - -    - - - - Phreatic activity Uncertain
   - - - -    - - - - Ash
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Property Damage
1974 Feb 26    - - - - VEI (Explosivity Index)

1973 Jan 24 - 1973 Jan 25 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1973 Jan 24 - 1973 Jan 25 Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Phreatic activity weak or small
   - - - -    - - - - Ash
1973 Jan 24    - - - - VEI (Explosivity Index)

1964 Feb 14 - 1964 Feb 14 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1964 Feb 14 - 1964 Feb 14 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
1964 Feb 14    - - - - VEI (Explosivity Index)

1940 Jul Confirmed Eruption VEI: 2

Episode 1 | Eruption
1940 Jul - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1940 Jul    - - - - VEI (Explosivity Index)

1939 Dec 19 - 1940 Feb 21 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1939 Dec 19 - 1940 Feb 21 Evidence from Observations: Reported

List of 7 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Lahar or Mudflow
   - - - -    - - - - Property Damage
1939 Dec 19    - - - - VEI (Explosivity Index)
1940 Jan 30    - - - - VEI (Explosivity Index)

1939 Jul 18 - 1939 Jul 30 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1939 Jul 18 - 1939 Jul 30 Evidence from Observations: Reported

List of 5 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Property Damage
1939 Jul 18    - - - - VEI (Explosivity Index)

1936 Nov 26 - 1936 Nov 27 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1936 Nov 26 - 1936 Nov 27 Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
1936 Nov 26    - - - - VEI (Explosivity Index)

1934 Jan 24 - 1934 Apr 25 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1934 Jan 24 - 1934 Apr 25 Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Property Damage
1934 Jan 24    - - - - VEI (Explosivity Index)

1926 Apr 22 - 1926 Apr 24 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1926 Apr 22 - 1926 Apr 24 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Blocks
1926 Apr 22    - - - - VEI (Explosivity Index)

1923 May 19 (?) - 1923 May 19 (?) Confirmed Eruption VEI: 1

Episode 1 | Eruption
1923 May 19 (?) - 1923 May 19 (?) Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1923 May 19
(?)
   - - - - VEI (Explosivity Index)

1921 Apr - 1921 Apr Confirmed Eruption VEI: 1

Episode 1 | Eruption
1921 Apr - 1921 Apr Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1921 Apr    - - - - VEI (Explosivity Index)

1908 Feb 16 - 1908 Feb 17 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1908 Feb 16 - 1908 Feb 17 Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity Uncertain
   - - - -    - - - - Ash weak or small
1908 Feb 16    - - - - VEI (Explosivity Index)

1905 Confirmed Eruption VEI: 0

Episode 1 | Eruption
1905 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1905    - - - - VEI (Explosivity Index)

1900 Oct 26 - 1900 Oct 27 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1900 Oct 26 - 1900 Oct 27 Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1900 Oct 26    - - - - VEI (Explosivity Index)

1900 Jun 4 - 1900 Jun 4 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1900 Jun 4 - 1900 Jun 4 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
1900 Jun 4    - - - - VEI (Explosivity Index)

1895 Jul 2 - 1895 Sep 30 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1895 Jul 2 - 1895 Sep 30 Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Audible Sounds
1895 Jul 2    - - - - VEI (Explosivity Index)

1884 Jun - 1884 Jul Confirmed Eruption VEI: 2

Episode 1 | Eruption
1884 Jun - 1884 Jul Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1884 Jun    - - - - VEI (Explosivity Index)

1881 Dec - 1881 Dec Confirmed Eruption VEI: 2

Episode 1 | Eruption
1881 Dec - 1881 Dec Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1881 Dec    - - - - VEI (Explosivity Index)

1881 Feb 16 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1881 Feb 16 - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Earthquakes (undefined)
1881 Feb 16    - - - - VEI (Explosivity Index)

1880 May Confirmed Eruption VEI: 2

Episode 1 | Eruption
1880 May - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1880 May    - - - - VEI (Explosivity Index)

1879 May 18 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1879 May 18 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1879 May 18    - - - - VEI (Explosivity Index)

1853 Jan 1 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1853 Jan 1 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1853 Jan 1    - - - - VEI (Explosivity Index)

1839 (?) Confirmed Eruption VEI: 2

Episode 1 | Eruption
1839 (?) - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1839
(?)
   - - - - VEI (Explosivity Index)

1817 Dec 31 ± 365 days Confirmed Eruption VEI: 2

Episode 1 | Eruption
1817 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
1817 Dec 31 ± 365 days    - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Dempo.

Emission History

There is no Emissions History data available for Dempo.

Photo Gallery

A meteorological cloud rises above the summit of Dempo stratovolcano in SE Sumatra, towering nearly 3 km above tea plantations below its E flank. Dempo has produced frequent historical recent small-to-moderate explosive eruptions. The summit contains seven partially overlapping craters, the youngest of which is partially filled by a crater lake.

Photo by Deddy Rochendi, 1981 (Volcanological Survey of Indonesia).
The youngest crater of Dempo volcano, at the WNW end of a series of six partially overlapping craters at the summit, contains a 400-m-wide crater lake that has been the source of frequent phreatic eruptions during historical time. A seventh smaller crater is located on the upper N flank. Dempo is one of Sumatra's most active volcanoes, frequently producing small-to-moderate explosive eruptions.

Photo by Ruska Hadian, 1989 (Volcanological Survey of Indonesia).
The crater wall of Kawah Merapi, the youngest and NW-most of the craters along the summit of Dempo volcano, is capped by thin lava flows. A crater lake is seen at the lower right in this view from the NE. Gunung Merapi, the high point of the summit region of Dempo volcano, occurs at the extreme left at the SE part of the crater rim.

Photo by Ruska Hadian, 1989 (Volcanological Survey of Indonesia).
The crater wall above the historically active crater lake within Kawah Merapi crater at the summit of Dempo volcano shows a series of alternating lava flows and pyroclastic deposits.

Photo by Ruska Hadian, 1989 (Volcanological Survey of Indonesia).
A scientist from the Volcanological Survey of Indonesia investigates rocks in the summit crater of Dempo volcano. The Kawah Merapi crater exposes bedded pyroclastic material that is overlain by a series of light-colored lava flows.

Photo by R. Whandyo, 1992 (Volcanological Survey of Indonesia).
An aerial view from the N shows the summit crater of Dempo volcano to the upper left. The steep-walled crater contains a lake, which has been the source of frequent phreatic eruptions during historical time.

Anonymous, 1991.
Gunung Dempo, one of the most active volcanoes of Sumatra, has a conical profile when viewed from the village of Pager Alam below the eastern flank of the volcano. The summit contains nested craters on its NW side.

Photo by Sumarma Hamidi, 1972 (Volcanological Survey of Indonesia).
GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

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

External Sites