Slamet

Photo of this volcano
Google Earth icon
  Google Earth Placemark
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 7.242°S
  • 109.208°E

  • 3428 m
    11244 ft

  • 263180
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 17 September-23 September 2014


PVMBG reported that during 13-16 September white plumes rose 50-200 m above Slamet's crater. An explosion on 17 September produced a dense blackish-gray ash plume that rose as high as 1.2 km and drifted S and SW. Incandescent material was ejected 200-500 m high and booming noises were reported. Ash fell in areas as far as 20 km S. Although white plumes mostly rose from the crater the next day, an explosion generated an ash plume that rose 500 m and drifted W. During 19-20 September white plumes rose 100 m. The Alert Level remained at 3 (on a scale of 1-4).

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


Most Recent Bulletin Report: January 2010 (BGVN 35:01)


Explosions send tephra ~700 m above summit through at least June 2009

Minor explosions at Slamet with occasional lava fountains and small ash plumes occurred from April through early June 2009 (BGVN 34:05). During the rest of June 2009, this activity continued. The Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported that during 8-28 June, tephra was ejected 50-700 m above the crater. In addition, incandescent material was ejected 50-300 m above the crater. Booming noises were also reported. During 23-29 June, incandescence and ash emissions were not observed. On 29 June, CVGHM lowered the Alert Level for Slamet to 2 (on a scale of 1-4) because of decreased seismicity and emissions.

Based on pilot observations, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that on 8 August and 12 September 2009 ash plumes rose above the summit. In neither case was ash identified on satellite imagery.

June 2009 observations at the summit. Thorsten Boeckel and Martin Rietze climbed Slamet on 13 June 2009 and spent a night at the summit and at their camp at 3,200 m (figure 3). They said that reports issued prior to their climb noted plumes up to 700 m above the summit, but the activity later decreased to a point where the risk of being struck by a volcanic bomb had diminished, though hard hats were worn. These photographers have considerable experience on active volcanoes. Besides Strombolian eruptions, gas-fed flames sometimes reached ~ 20 m high (figure 3).

Figure 3. Photos of Slamet taken on 13-14 June 2009, with most shot from the E crater rim. (A) One viewpoint for watching the crater. (B) Night scene showing two glowing vents at the top of the intracrater cone. (C-D) Night scenes with lava fountains, sprays of spatter, and flames near the vent. In daylight, one scene taken amid comparative calm (E) and sudden explosions (F-G). (H) Flames at the far vent, appearing as a broad luminous zone. Courtesy of Rietze and Boeckel.

Approaching the summit they observed the vent to assess the risk and ultimately felt secure in advancing to more exposed positions on the rim. Deafening noise came from the two vents in the middle of the ~ 100-m wide intra-crater cinder cone. Figure 3 (B and E) present overviews of the active crater area. Two vents were glowing.

Initially, each eruption had a similar character, starting with a emission of gas and flames with a slightly blue-green color rising ~ 5 m above the vent. These emissions and flames later grew to reach ~ 20 m above the vent. As the eruptions proceeded the emissions became increasingly red. Eventually there was an explosion and lava fountains jetted up to ~ 200 m above the vent. Occasionally a second vent glowed (figure 3, B and D, and due to flames in H).

Fog at the crater made photography difficult at times. Strong luminosity from the gas flames would sometimes overexpose a portion of the photo. As dawn approached, more forceful tephra emissions generated billowing ash clouds (figure 3, F and G). Next, the loudest detonation of their stay occurred, but explosions did not become more violent over the next 6 hours.

Boeckel and Rietze had observed flames here in 2006. Rietze, who has visited more than 24 volcanoes, said he had never seen such impressive flames as those at Slamet: "These flames [during the 2009 visit (figure 3 H)] were up to 10-20 m high...shining intensely even without ejecta. In fact this was the reason why all long exposure images were burnt out in the center, it was not possible to photograph the Strombolian phases as with other volcanoes due to this. Of [course, the flames] changed from time to time, sometimes there were flames only, and sometimes only Strombolian phases."

Boeckel and Rietze also presented videos of vigorous flames on their websites. The cause of the flames remains uncertain in the absence of instrumental (eg., spectrometer) data. Occasional reports of combustion and flames are known at volcanoes, for example, from combustion of methane, or hydrogen (the latter, discussed by Naughton, 1973), and flames of various colors were documented in the 1943-1951 eruptions at Parícutin (Luhr and Simkin, 1993). In addition, the eruption of Tolbachik in July 1975 generated flames (Fedotov, 1984), and blue flames were associated with active vents preceding the 18 May 1980 eruption at St. Helens (SEAN 05:03).

During Rietze and Boeckel's 2006 visit, the active intracrater cone contained pits in both the middle and flank areas, with hundreds of small deep-orange flames (up to 2 m high) constantly burning. By 2009 the pits had filled up with debris, but new vents atop this area emitted burning gas and bursts of lava.

References. Fedotov, S.A. (ed.), 1984, The Great Fissure Tolbachik eruption, Kamchatka 1975-1976: Nauka, Moscow, Academy of Sciences of the USSR Far East Science Center, Institute of Volcanology, 637 p. (in Russian).

Luhr, J., and Simkin, T., 1993, Parícutin?The volcano born in a Mexican cornfield: Geoscience Press, Phoenix, Arizona, USA. 427 p.

Naughton, J.J., 1973, Volcanic flame: source of fuel and relation to volcanic gas-lava equilibrium: Geochimica et Cosmochimica Acta (Elsevier Ltd.), v. 37, no. 5, May 1973, p. 1163-1169, doi:10.1016/0016-7037(73)90053-7

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://portal.vsi.esdm.go.id/joomla/); 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/); Thorsten Boeckel (URL: http://www.tboeckel.de/) and Martin Rietze (URL: http://mrietze.com/i-Slamet09.htm).

Index of Weekly Reports


2014: March | April | May | July | August | September
2011: July
2009: April | May | June | August | September
2007: March

Weekly Reports


17 September-23 September 2014

PVMBG reported that during 13-16 September white plumes rose 50-200 m above Slamet's crater. An explosion on 17 September produced a dense blackish-gray ash plume that rose as high as 1.2 km and drifted S and SW. Incandescent material was ejected 200-500 m high and booming noises were reported. Ash fell in areas as far as 20 km S. Although white plumes mostly rose from the crater the next day, an explosion generated an ash plume that rose 500 m and drifted W. During 19-20 September white plumes rose 100 m. The Alert Level remained at 3 (on a scale of 1-4).

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


10 September-16 September 2014

PVMBG reported explosive activity from Slamet during 4-12 September. During the past week, activity peaked with incandescent explosions; rumbling sounds were heard by scientists at the Slamet observation post. On 11 September the largest ash plume was observed (200-1,500 m above the summit) and incandescent plumes reached 400 m above the summit. Seismicity was dominated by emissions and explosion signals. Deformation data indicated that relatively little pressure was accumulating due to magma movement. PVMBG maintained the Alert Level 3 (on a scale of 1-4).

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


6 August-12 August 2014

PVMBG reported that during 1-12 August 100 thick gray ash plumes rose 300-800 m above the summit drifting N, E, and W, seismicity increased, and ejected material was deposited on the flanks 1.5 km from the crater on the W and SW at Slamet. Incandescence and rumbling/roaring noises were reported. The Alert Level was raised to 3 (on a scale of 1-4) on 12 August. Residents and tourists were warned not approach the crater within a radius of 4 km.

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


16 July-22 July 2014

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 18 July a low level plume from Slamet rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted 83 km W and N.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


9 July-15 July 2014

CVGHM reported that incandescence had been visible 14 times in May and there were ash eruptions reaching 150-1,500 m above Slamet’s summit that drifted NW and W. White plumes were typically visible 50-800 m above the summit in May and June. There were 14 moderate ash eruptions during 15-30 June that generated plumes 500-1,400 m above the summit and drifted N and W. Incandescence was visible three times in June. During 1-2 July, there were 17 moderate ash plumes that generated plumes 300-1,200 m above the summit that drifted N and W. Alert Level 2 was maintained and visitors and tourists were prohibited from approaching the crater within a radius of 2 km.

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


14 May-20 May 2014

BNPB reported that the Alert Level for Slamet was lowered to 2 (on a scale of 1-4) on 12 May because activity had decreased. Visitors and tourists were prohibited from approaching the crater within a radius of 2 km.

Source: Badan Nacional Penanggulangan Bencana (BNPB)


30 April-6 May 2014

PVMBG reported that during 29 March-30 April seismicity at Slamet increased and inflation was detected. Observers noted that white plumes rose as high as 800 m above the crater, and dense gray ash plumes rose as high as 2 km and drifted E and W. During 19-25 April the plumes were gray to brown, and ejected material was deposited on the flanks 300 m from the crater. Crater incandescence was noted. During 26-30 April the ash plumes continued to have a brownish component, and material fell in areas within 1.5 km W. The crater was again incandescent. Rumbling noises were reported and windows at the Slamet observation post rattled during 27-29 April. The Alert Level was raised to 3 (on a scale of 1-4) on 30 April. Residents and tourists were warned not approach the crater within a radius of 4 km.

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


26 March-1 April 2014

PVMBG reported that during 8-14 March dense white plumes rose as high as 1.2 km above Slamet, and ash plumes rose 800-1,000 m and drifted E. Incandescence from the crater was observed at 2148 during an eruption on 14 March. Brownish-white plumes rose 2 km on 15 March and ash plumes rose 1.2 km and again drifted E. During 22-28 March white-to-gray plumes rose 1.3 km. Dense gray ash plumes rose 2 km and drifted W. White plumes were observed on 29 March. Various seismic signals including shallow volcanic earthquakes, harmonic tremor, and volcanic earthquakes fluctuated during 8-28 March. Carbon dioxide emissions significantly increased during 17-20 March. PVMBG noted that activity, based on visual and instrument monitoring, continued to fluctuate; on 29 March the Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were warned not approach the crater within a radius of 2 km.

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


5 March-11 March 2014

PVMBG reported that seismicity at Slamet increased during 1-10 March, particularly during 8-10 March. Observers at a post in Slamet Gambuhan village, about 10 km away, noted that diffuse to dense white plumes rose as high as 600 m above the crater during 1-7 March, and as high as 1 km during 8-10 March. The Alert Level was raised to 2 (on a scale of 1-4) on 10 March; visitors and tourists were advised not to approach the crater within a radius of 2 km.

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


6 July-12 July 2011

CVGHM reported that between 6 September 2009 and July 2011 eruptions from Slamet had been absent and plumes (likely steam) rose as high as 500 m above the crater. Seismicity and the temperature of hot water from springs both decreased. On 11 July, the Alert Level was lowered to 1 (on a scale of 1-4).

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


9 September-15 September 2009

The Darwin VAAC reported that on 12 September a low-level ash plume from Slamet was observed by a pilot. Ash was not identified on satellite imagery.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


5 August-11 August 2009

Based on a pilot observation, the Darwin VAAC reported that on 8 August an ash plume from Slamet rose 90 m above the summit. Ash was not detected in satellite imagery.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


24 June-30 June 2009

CVGHM reported that during 8-28 June tephra was ejected 50-700 m above Slamet's crater and incandescent material was ejected 50-300 m above the crater. Booming noises were reported. During 23-29 June, incandescence and ash emissions were not observed. On 29 June, CVGHM lowered the Alert Level for Slamet to 2 (on a scale of 1-4) because of decreased seismicity and emissions.

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


3 June-9 June 2009

CVGHM reported that during 26 May-4 June activity from Slamet fluctuated, but decreased overall. The number of earthquakes and the temperature of water in areas around the volcano were lower. Inflation and deflation fluctuated within a range of 2 cm. White plumes rose 100-750 high. During 5-7 June, activity was characterized by inflation and an increased number of earthquakes. During that time, white plumes were accompanied by ash emissions that rose 200-800 m from the crater, incandescent material was ejected 50-200 m above the crater, and booming noises were reported. The Alert Level remained at 3 (on a scale of 1-4).

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


27 May-2 June 2009

Based on ground information from CVGHM, the Darwin VAAC reported that on 27 May an ash plume from Slamet rose to an altitude of 4.3 km (14,000 ft) a.s.l. Analysis of satellite imagery indicated that a possible plume rose to an altitude of 6.1 km (20,000 ft) a.s.l., but ash was not conclusively detected.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


20 May-26 May 2009

On 26 May, CVGHM reported that since 21 April seismicity from Slamet continued to increase or remain elevated; the peak of activity was on 17 May. White-to-brown "eruption smoke" rose about 800 m above the crater and inflation was detected. Ashfall was detected in areas 5-9 km away. The temperature of water in several locations on the flanks increased. During 12 and 21-23 May, lava fountains rose 100-400 m above the crater rim. White-to-gray "smoke" rose 150 m above the crater and ejected incandescent material onto the W flank. On 22 May, ashfall was reported in Sawangan village, 5 km W. On 23 May, an ash plume rose 1 km above the crater and ash fell on the N flank. Ash accumulated to1 mm near the observation post. The next day, an ash plume rose 700 m above the crater. The Alert Level remained at 3 (on a scale of 1-4).

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


29 April-5 May 2009

During 23 April-5 May, CVGHM reported that seismicity from Slamet increased and an eruption originating from the western part of the crater continued. During times of clear weather, observers reported that incandescent lava, ejected 25-100 m above the crater, fell back into and around the active crater. Gray and white "smoke" rose 100-800 m from the crater. Occasionally a "thunderous" noise accompanied eruptions of ash. The Alert Level remained at 3 (on a scale of 1-4).

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


22 April-28 April 2009

CVGHM reported that seismicity from Slamet increased during 19-23 April. Diffuse white plumes rose about 50 m above the crater on 20 April. During 21-23 April, white and white-to-brownish plumes rose 50-800 m above the crater. On 23 April, the Alert Level was raised to 3 (on a scale of 1-4); people were advised not to climb the summit. According to a news article, a CVGHM volcanologist stated that lava was ejected 600 m high and ash bursts up to 112 times within a 6-hour period were detected.

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


28 March-3 April 2007

According to a news article, a volcano observer monitoring Slamet reported on 1 April that plume activity had increased in intensity and frequency over the previous two weeks. Plumes rose to an estimated altitude of 3.8 km (12,500 ft) a.s.l.

Source: Earth Times


Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

06/1988 (SEAN 13:06) Incandescent tephra; ashfall to 85 km

07/1988 (SEAN 13:07) Activity decreases to quiet fuming

11/1989 (SEAN 14:11) Increased seismicity and gas emission

03/1991 (BGVN 16:03) Continued gas emission

06/1991 (BGVN 16:06) Plume emission follows harmonic tremor episodes

03/1995 (BGVN 20:03) Increased seismicity and gas emission

11/1996 (BGVN 21:11) A modest steam plume and seismic signals during September

05/1999 (BGVN 24:05) Tremor and ash emission mark greatest unrest since last eruption in 1989

08/1999 (BGVN 24:08) Ash emissions June-September; new seismograph measures constant tremor

11/2000 (BGVN 25:11) During May-October 2000, continuous tremor and abundant explosion earthquakes

04/2008 (BGVN 33:04) Heavy rains trigger steam plumes during 28 March-3 April 2007

05/2009 (BGVN 34:05) During April-June 2009, minor explosive eruptions with occasional lava fountains

01/2010 (BGVN 35:01) Explosions send tephra ~700 m above summit through at least June 2009




Bulletin Reports

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


06/1988 (SEAN 13:06) Incandescent tephra; ashfall to 85 km

Slamet began to erupt ash and incandescent tephra at about 1800 on [12] July. At 0700 the next morning, explosions were occurring once a minute, ejecting incandescent fragments to 500 m above the vent. Ash fell 45 and 85 km NE at Cirebon and Brebes. By 1500, eruptive activity had stopped but heavy fuming continued from one of the active craters, feeding an 800-m plume. The moderate activity was consistent with most of the volcano's 38 eruptions in the past 200 years and no evacuation was ordered.

The eruption was preceded by periods of brief harmonic tremor on 9 July and six hours of increased seimicity including brief tremor episodes on 10 July. A second radio-telemetered seismometer will be installed on the volcano.

Information Contacts: VSI.

07/1988 (SEAN 13:07) Activity decreases to quiet fuming

The eruption that began on 12 July ejected incandescent lava to 100 m above the summit, accompanied by a 200-m fume cloud. Similar activity continued the next day [see also 14:11]. Between 14 and 19 July, heavy fuming produced an 800-m light-colored plume. After 19 July, only quiet fuming persisted. No evacuations were necessary.

Information Contacts: VSI.

11/1989 (SEAN 14:11) Increased seismicity and gas emission

Increased seismicity (table 1) and gas emission have been observed at Slamet since the second week in October. A white plume rose as much as 300 m, compared to 100-150 m the previous week. Geologists noted that a small eruption could occur at any time. The alert level has been increased and local officials have been notified. Slamet's most recent activity was a weak 30-hour Strombolian eruption 12-13 July [1988], preceded by tremor that began at 1145. No casualties were reported.

Table 1. Seismicity recorded at Slamet, 7-10 October 1989. S-P of A-type events is 1.5-4 seconds. Courtesy of VSI.

    Seismicity       A-type   B-type   Degassing

    07 October 89       -        1         11
    08 October 89       -        -         30
    09 October 89      25       18        200
    10 October 89     200       10         11

Information Contacts: VSI.

03/1991 (BGVN 16:03) Continued gas emission

The crater was covered by thick solfataric gas, but no significant changes were observed during fieldwork. Earthquakes associated with gas emissions were recorded an average of 776 times/day.

Information Contacts: W. Modjo, VSI; AP.

06/1991 (BGVN 16:06) Plume emission follows harmonic tremor episodes

Harmonic tremor episodes (average frequency 2.5 Hz) began at 1730 on 24 June and were continuing as of early July. A dense 200-m-high plume was observed on 28 June. COSPEC measurements, started on 29 June, yielded SO2 fluxes of 66-87 t/d, compared to 30 t/d in 1988.

Information Contacts: W. Modjo, VSI.

03/1995 (BGVN 20:03) Increased seismicity and gas emission

Seismicity increased in January-February 1995. Continuous volcanic tremor (maximum amplitude 21 mm) was recorded during 14-19 January, followed by intermittent tremor (maximum amplitude 10 mm) until 26 January and during 6-10 February. Earthquakes associated with gas emissions were recorded at an average rate of 50 events/day in late January; by the end of February these had increased to 150 events/day (figure 06sla01f). No explosive activity was observed or detected.

Figure 1. Daily number of gas-emission earthquakes and tremor amplitude at Slamet, January-February 1995. Courtesy of VSI.

Information Contacts: W. Tjetjep, VSI.

11/1996 (BGVN 21:11) A modest steam plume and seismic signals during September

During September steam rose 150 m over the summit and seismic signals continued.

Information Contacts: Wimpy S. Tjetjep, Volcanological Survey of Indonesia, Jalan Diponegoro No. 57, Bandung 40122, Indonesia (Email: vsimvo@ibm.net).

05/1999 (BGVN 24:05) Tremor and ash emission mark greatest unrest since last eruption in 1989

Mount Slamet has been predominantly quiet since its last eruption in 1989. During the week of 27 April-3 May, however, the volcano's status was raised to "Alert." That week and the next, "white ash emissions" reached 400 m and hot-spring temepratures ranged from 40 to 81°C. Tremors constituted the dominate seismic events. Slamet ejected black ash from its crater over 1-2 May, prompting concern. Government officials warned residents to stay away from the area following several outbursts within a 10-day period.

During 4-17 May seismicity was dominated by tremor with 4- to 30-mm amplitudes, and "thin-to-thick white ash plumes" reached 400 m height. During 18-24 May ash plumes only rose 25-100 m; tremor amplitudes declined to 0.5-20 mm. There was an increase in volcanic events, with B-type events increasing from 9 to 68 and A-type increasing from 10 to 26.

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

08/1999 (BGVN 24:08) Ash emissions June-September; new seismograph measures constant tremor

Moderate eruptive activity at Slamet, including ash emission and seismicity of varying intensity, continued during June-September. On most days during this period a "thick white plume of ash" rose as high as 600 m above the summit. The thickness of the ash cloud increased in September.

A new PS-2 type seismograph was added to the existing seismic monitoring network on 29 May. Tremor with amplitudes ranging from 0.5 to 15 mm was the dominant seismic type recorded during June. During 15-21 June tremor amplitudes ranged from 3-30 mm. In July small explosion earthquakes prevailed. Beginning in late July and continuing to 20 September, tremor was nearly constant with amplitudes up to 15 mm. Seismicity tended to increase toward the end of September (figure 2).

Figure 2. Number of volcanic earthquakes (A- and B-type) recorded at Slamet during June-September 1999. Data courtesy of VSI.

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

11/2000 (BGVN 25:11) During May-October 2000, continuous tremor and abundant explosion earthquakes

The following report covers mid-May to late October 2000. Activity increased during the third week of May when tremor events commonly reached amplitudes of 0.5-10 mm, and a white low-density plume rose 50-400 m above the summit. By the second week of June maximum tremor amplitudes reached 15 mm. A white gas-rich plume rose up to 200 m above the summit. In the last week of July, seismographs recorded 713 small explosion earthquakes along with tremor, and a dense white plume rose 300 m.

Similar activity persisted through mid-September, when tremor became continuous. The number of small explosion earthquakes increased; seismographs registered 3,244 events during 19-25 September, and 3,765 were registered during 26 September-2 October. A white, variable-density plume erupted continuously during the latter period. After 3 October, however, activity decreased significantly with explosion earthquakes decreasing in number to 199 during the next week. By mid-October both visual and instrumental monitoring confirmed a decrease in eruptive energy. Near the end of the month a low-density plume rose up to 300 m above the summit, but only volcanic tremor was recorded.

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

04/2008 (BGVN 33:04) Heavy rains trigger steam plumes during 28 March-3 April 2007

Our last review of Slamet's activity was in November 2000, reporting a white, gas-rich plume from the stratovolcano (BGVN 25:11). We are unaware of subsequent reporting until 28 March 2007. Starting that day and through 3 April, a volcano observer reported that plumes had increased in intensity and frequency. This 7-day interval took place after two weeks of heavy rains. The plumes were of sufficient magnitude to be visible in the provincial capital, Semarang, over 138 km to the ENE. The plumes did not significantly impact residents in vicinity of the volcano. Thermal anomalies (MODVOLC) have been absent on the upper cone during 2000 through 5 June 2008.

Information Contacts: Dali Ahmad, Center of Volcanology and Geological Hazard Mitigation, Saut Simatupang, 57, Bandung 40122, Indonesia (URL: http://portal.vsi.esdm.go.id/joomla/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/).

05/2009 (BGVN 34:05) During April-June 2009, minor explosive eruptions with occasional lava fountains

Minor eruptions were reported at the active crater during April-June 2009. Small amounts of ash fell several times during May. Witnesses saw lava fountains on 12 and 21-23 May. Previously, steam plumes were associated with heavy rains during 28 March-3 April 2007 (BGVN 33:04).

During 19-23 April 2009 Slamet's seismicity increased. On 20 April, diffuse white plumes rose ~ 50 m above the crater. During 21-23 April, the number of eruption tremors increased steadily, and dense, white-to-brownish plumes rose 50-800 m above the crater rim. The Alert Level was raised to 2 (on a scale of 1-4).

On 23 April, the Alert Level was raised to 3; people were advised not to climb the summit. According to a news article in the Jakarta Globe, a volcanologist from the Center of Volcanology and Geological Hazard Mitigation (CVGHM) stated that lava was ejected 600 m high and ash bursts occurred up to 112 times within a 6-hour period.

According to CVGHM, seismicity continued to increase or remain elevated during 23 April-17 May, peaking on 17 May. During this period, continuous eruptive quakes/tremors were recorded, together with an increase in amplitude (3-46 mm on 12-13 May, rising to about 20-32 mm between 17-24 May). Eruptions from the western part of the crater continued, and inflation was noted. During times of clear weather, observers reported that incandescent lava was ejected 25-100 m above the crater, and then fell back into and around the active crater. Gray and white "smoke" rose 100-800 m from the crater. Occasionally a thunderous noise accompanying eruptions of ash occurred, and ashfall was detected in areas 5-9 km away. The temperature of water in several locations on the flanks increased.

During 12 May and 21-23 May, lava fountains rose 100-400 m above the crater rim. During several eruptions, ejected incandescent material traveled down the W flank. White-to-gray "smoke" rose 150 m above the crater. On 22 May, ashfall was reported in Sawangan village, 5 km W. On 23 May, an ash plume rose 1 km above the crater and ash fell on the N flank. Ash accumulated to 1 mm depth near the observation post. The next day an ash plume rose 700 m above the crater.

Based on ground information from CVGHM, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that on 27 May an ash plume from Slamet rose to an altitude of 4.3 km. Analysis of satellite imagery also indicated that a possible plume rose to an altitude of 6.1 km, but ash was not conclusively detected.

CVGHM reported that during 26 May-4 June activity from Slamet fluctuated, but decreased overall. They found decreases in both the number of earthquakes and the temperature of water in areas around the volcano. Inflation and deflation fluctuated within a range of 2 cm. White plumes rose 100-750. During 5-7 June, activity was characterized by inflation and an increased number of earthquakes. During that time, white plumes were accompanied by ash emissions that rose 200-800 m from the crater, incandescent material was ejected 50-200 m above the crater, and booming noises were reported.

As of 4 June 2009, the Alert Level remained at 3, based on visual data, deformation, earthquakes, and tremor. CVGHM urged the public to don face masks during heavy ashfalls, and to cover water sources to prevent contamination by volcanic ash.

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

01/2010 (BGVN 35:01) Explosions send tephra ~700 m above summit through at least June 2009

Minor explosions at Slamet with occasional lava fountains and small ash plumes occurred from April through early June 2009 (BGVN 34:05). During the rest of June 2009, this activity continued. The Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported that during 8-28 June, tephra was ejected 50-700 m above the crater. In addition, incandescent material was ejected 50-300 m above the crater. Booming noises were also reported. During 23-29 June, incandescence and ash emissions were not observed. On 29 June, CVGHM lowered the Alert Level for Slamet to 2 (on a scale of 1-4) because of decreased seismicity and emissions.

Based on pilot observations, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that on 8 August and 12 September 2009 ash plumes rose above the summit. In neither case was ash identified on satellite imagery.

June 2009 observations at the summit. Thorsten Boeckel and Martin Rietze climbed Slamet on 13 June 2009 and spent a night at the summit and at their camp at 3,200 m (figure 3). They said that reports issued prior to their climb noted plumes up to 700 m above the summit, but the activity later decreased to a point where the risk of being struck by a volcanic bomb had diminished, though hard hats were worn. These photographers have considerable experience on active volcanoes. Besides Strombolian eruptions, gas-fed flames sometimes reached ~ 20 m high (figure 3).

Figure 3. Photos of Slamet taken on 13-14 June 2009, with most shot from the E crater rim. (A) One viewpoint for watching the crater. (B) Night scene showing two glowing vents at the top of the intracrater cone. (C-D) Night scenes with lava fountains, sprays of spatter, and flames near the vent. In daylight, one scene taken amid comparative calm (E) and sudden explosions (F-G). (H) Flames at the far vent, appearing as a broad luminous zone. Courtesy of Rietze and Boeckel.

Approaching the summit they observed the vent to assess the risk and ultimately felt secure in advancing to more exposed positions on the rim. Deafening noise came from the two vents in the middle of the ~ 100-m wide intra-crater cinder cone. Figure 3 (B and E) present overviews of the active crater area. Two vents were glowing.

Initially, each eruption had a similar character, starting with a emission of gas and flames with a slightly blue-green color rising ~ 5 m above the vent. These emissions and flames later grew to reach ~ 20 m above the vent. As the eruptions proceeded the emissions became increasingly red. Eventually there was an explosion and lava fountains jetted up to ~ 200 m above the vent. Occasionally a second vent glowed (figure 3, B and D, and due to flames in H).

Fog at the crater made photography difficult at times. Strong luminosity from the gas flames would sometimes overexpose a portion of the photo. As dawn approached, more forceful tephra emissions generated billowing ash clouds (figure 3, F and G). Next, the loudest detonation of their stay occurred, but explosions did not become more violent over the next 6 hours.

Boeckel and Rietze had observed flames here in 2006. Rietze, who has visited more than 24 volcanoes, said he had never seen such impressive flames as those at Slamet: "These flames [during the 2009 visit (figure 3 H)] were up to 10-20 m high...shining intensely even without ejecta. In fact this was the reason why all long exposure images were burnt out in the center, it was not possible to photograph the Strombolian phases as with other volcanoes due to this. Of [course, the flames] changed from time to time, sometimes there were flames only, and sometimes only Strombolian phases."

Boeckel and Rietze also presented videos of vigorous flames on their websites. The cause of the flames remains uncertain in the absence of instrumental (eg., spectrometer) data. Occasional reports of combustion and flames are known at volcanoes, for example, from combustion of methane, or hydrogen (the latter, discussed by Naughton, 1973), and flames of various colors were documented in the 1943-1951 eruptions at Parícutin (Luhr and Simkin, 1993). In addition, the eruption of Tolbachik in July 1975 generated flames (Fedotov, 1984), and blue flames were associated with active vents preceding the 18 May 1980 eruption at St. Helens (SEAN 05:03).

During Rietze and Boeckel's 2006 visit, the active intracrater cone contained pits in both the middle and flank areas, with hundreds of small deep-orange flames (up to 2 m high) constantly burning. By 2009 the pits had filled up with debris, but new vents atop this area emitted burning gas and bursts of lava.

References. Fedotov, S.A. (ed.), 1984, The Great Fissure Tolbachik eruption, Kamchatka 1975-1976: Nauka, Moscow, Academy of Sciences of the USSR Far East Science Center, Institute of Volcanology, 637 p. (in Russian).

Luhr, J., and Simkin, T., 1993, Parícutin?The volcano born in a Mexican cornfield: Geoscience Press, Phoenix, Arizona, USA. 427 p.

Naughton, J.J., 1973, Volcanic flame: source of fuel and relation to volcanic gas-lava equilibrium: Geochimica et Cosmochimica Acta (Elsevier Ltd.), v. 37, no. 5, May 1973, p. 1163-1169, doi:10.1016/0016-7037(73)90053-7

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://portal.vsi.esdm.go.id/joomla/); 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/); Thorsten Boeckel (URL: http://www.tboeckel.de/) and Martin Rietze (URL: http://mrietze.com/i-Slamet09.htm).

Slamet, Java's second highest volcano at 3428 m and one of its most active, has a cluster of about three dozen cinder cones on its lower SE-NE flanks and a single cinder cone on the western flank. It is composed of two overlapping edifices, an older basaltic-andesite to andesitic volcano on the west and a younger basaltic to basaltic-andesite one on the east. Gunung Malang II cinder cone on the upper E flank on the younger edifice fed a lava flow that extends 6 km E. Four craters occur at the summit of Gunung Slamet, with activity migrating to the SW over time. Historical eruptions, recorded since the 18th century, have originated from a 150-m-deep, 450-m-wide, steep-walled crater at the western part of the summit and have consisted of explosive eruptions generally lasting a few days to a few weeks.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2014 Mar 8 2014 Sep 18 (continuing) Confirmed 2 Historical Observations
2009 Apr 21 2009 Jun 22 (?) Confirmed 1 Historical Observations
[ 2000 Jul (?) ] [ 2000 Oct (?) ] Uncertain 1  
1999 May 1 (?) 1999 Sep (?) Confirmed 1 Historical Observations
1988 Jul 12 1988 Jul 13 Confirmed 1 Historical Observations
[ 1974 May 29 ] [ 1974 May 29 ] Uncertain 2  
1973 Aug Unknown Confirmed 1 Historical Observations
1969 Jun 23 1969 Aug Confirmed 2 Historical Observations
1967 May 7 1967 Jul Confirmed 2 Historical Observations
1966 Unknown Confirmed 2 Historical Observations
1960 Dec 1961 Jan Confirmed 2 Historical Observations
1958 Sep 13 1958 Nov 5 ± 4 days Confirmed 2 Historical Observations
1958 Apr 17 1958 May 7 Confirmed 2 Historical Observations
1957 Feb 8 1957 Feb 8 Confirmed 2 Historical Observations
1955 Nov 12 1955 Dec 20 (?) Confirmed 2 Historical Observations
1953 Aug 1953 Oct Confirmed 2 Historical Observations
1951 Jun 26 1952 Jan 1 Confirmed 2 Historical Observations
1951 Feb 11 Unknown Confirmed 2 Historical Observations
1948 Nov 14 1948 Dec 15 Confirmed 2 Historical Observations
1944 May 9 1944 Oct 30 Confirmed 2 Historical Observations
1943 Oct 2 1944 Jan 5 Confirmed 2 Historical Observations
[ 1943 Mar 18 ] [ Unknown ] Uncertain    
1940 Mar 15 1940 Apr 15 Confirmed 2 Historical Observations
1939 Dec 4 1939 Dec 4 Confirmed 2 Historical Observations
1939 Mar 29 1939 Jul 15 Confirmed 2 Historical Observations
1937 Unknown Confirmed   Historical Observations
[ 1934 ] [ Unknown ] Uncertain    
1933 May 12 1933 May 13 Confirmed 1 Historical Observations
1932 Jul 1 1932 Sep 10 Confirmed 2 Historical Observations
1930 Apr 2 1930 Apr 13 Confirmed 2 Historical Observations
1929 Jun 6 1929 Jun 15 Confirmed 2 Historical Observations
1928 Mar 20 1928 May 12 Confirmed 2 Historical Observations
1927 Feb 27 1927 Feb 27 Confirmed 2 Historical Observations
1926 Nov 23 ± 1 days 1926 Nov 30 Confirmed 2 Historical Observations
1923 Jun 2 1923 Jun 2 Confirmed 2 Historical Observations
1904 Jul 14 1904 Aug 9 Confirmed 2 Historical Observations
1890 Aug 6 1890 Aug 29 Confirmed 2 Historical Observations
1885 Mar 21 1885 Mar 30 Confirmed 2 Historical Observations
1875 Nov 2 ± 2 days 1875 Dec 26 ± 5 days Confirmed 2 Historical Observations
1875 May 29 (in or before) 1875 Jun 4 ± 4 days Confirmed 2 Historical Observations
1860 Mar 19 1860 Apr 11 Confirmed 2 Historical Observations
1849 Dec 1 Unknown Confirmed 2 Historical Observations
1847 Mar 20 Unknown Confirmed 2 Historical Observations
1835 Sep 1835 Sep Confirmed 2 Historical Observations
1825 Oct Unknown Confirmed 2 Historical Observations
1772 Aug 11 1772 Aug 12 Confirmed 2 Historical Observations

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Synonyms

Slamat

Cones

Feature Name Feature Type Elevation Latitude Longitude
Cilekatan, Gunung Cone
Cilik, Gunung Cone
Kembang, Gunung Cone
Malang Ii, Gunung Cone
Malang, Gunung Cone
Sembung, Gunung Cone
Terbang, Gunung Cone 824 m
Gunung Slamet rises above farmlands on the northern coastal plain of central Java. The 3428-m-high stratovolcano, Java's second highest, is also one of its most active. The irregular ridge to the right of the sharp-peaked summit includes Gunung Penjara (right) and Gunung Malang, remnants of an older Slamet volcano.

Anonymous photo, 1987.
A steaming crater truncates the western side of 3428-m-high Slamet, Java's second highest volcano. Slamet is located along Java's narrow central waist. Four craters occur at the summit of Gunung Slamet, seen here from the SW. Historical eruptions at Slamet, one of Java's most active volcanoes, have been recorded since the 18th century and have originated from a 150-m-deep, 450-m-wide, steep-walled crater. The eruptions have generally been explosive, lasting a few days to a few weeks.

Photo by I. Pratomo, 1990 (Volcanological Survey of Indonesia).
Gunung Slamet, Java's second highest volcano, towers above the village of Kutabawa. The modern volcano forms a less-vegetated cone that rises above the forested slopes of an older volcano in the foreground. Slamet is one of Java's most active volcanoes and has produced frequent explosive eruptions recorded since the 18th century.

Photo by Igan Supriatna, 1990 (Volcanological Survey of Indonesia).
An aerial view from the SW of the summit of Slamet volcano shows the four overlapping craters capping the volcano. Activity has migrated to the SW, where the youngest and deepest crater is located. This crater, whose floor is obscured by clouds, is 450 m wide and more than 150 m deep.

Photo published in Taverne, 1926 "Vulkaanstudien op Java," (courtesy of Volcanological Survey of Indonesia).

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

Kusumadinata K, 1979. Data Dasar Gunungapi Indonesia. Bandung: Volc Surv Indonesia, 820 p.

Neumann van Padang M, 1951. Indonesia. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 1: 1-271.

Reubi O, Nicholls I A, Kamenetsky V S , 2003. Early mixing and mingling in the evolution of basaltic magmas: evidence from phenocryst assemblages, Slamet Volcano, Java, Indonesia. J Volc Geotherm Res, 119: 225-274.

Sutawidjaja I S, Aswin D, Sitorus K, 1985. Geologic map of Slamet volcano, Central Java. Volc Surv Indonesia, 1:50,000 geol map.

Taverne N J M, 1926. Vulkanstudien op Java. Vulk Meded, 7: 1-132.

Vukadinovic D, Nichols I A, 1989. The petrogenesis of island arc basalts from Gunung Slamet volcano, Indonesia: trace element and 87Sr/86Sr constraints. Geochim Cosmochim Acta, 53: 2349-2363.

Volcano Types

Stratovolcano
Pyroclastic cone(s)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Basalt / Picro-Basalt
Andesite / Basaltic Andesite
Minor
Dacite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
856
13,401
2,904,026
20,217,467

Affiliated Databases

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