Gamalama

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  • Indonesia
  • Indonesia
  • Stratovolcano(es)
  • 2012 CE
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  • Last Known Eruption
  • 0.8°N
  • 127.33°E

  • 1715 m
    5625 ft

  • 268060
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Most Recent Weekly Report: 10 October-16 October 2012


CVGHM reported that eruptions at Gamalama during 15-16 September prompted CVGHM to raise the Alert Level to 3 (on a scale of 1-4) on 16 September. An eruption on 17 September produced a white-and-gray plume that rose 300 m above the crater and drifted E and SE. Ashfall was reported in the ESE part of Ternate (S, SE, and E part of island). After the eruption through 8 October white plumes rose 10-50 m high. Seismicity decreased in early October. The Alert Level was decreased to 2 on 9 October. Visitors and residents were warned not to approach the crater within a radius of 1.5 km.

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


Most Recent Bulletin Report: November 2012 (BGVN 37:11)


Seismicity precedes small ash-bearing eruptions in September 2012

This report discusses a series of small but punctuated eruptions on 15-17 September 2012 associated with the return of seismicity at Gamalama. Fog obscured visibility but ash fell on inhabited areas. The eruptions were judged similar to those seen 4 December 2011 (BGVN 36:12).

As we noted previously, heavy rains after the 4 December 2011 eruptions led to lahars on 27-28 December that killed four people, injured dozens, and displaced thousands (BGVN 36:12). Photos showed that these lahars had carried many meter-diameter blocks into inhabited areas on the lower flanks. Videos from helicopter flights confirmed that in the upslope region, chutes and drainages had also fed finer ash into the lahars.

According to the Center for Volcanology and Geological Hazard Mitigation (CVGHM), on 24 January 2012, after witnessing an interval of generally reduced seismicity, an absence of significant ash-bearing plumes, and weak steam plumes rising only ~100 m above the summit, they lowered the Alert Level from 3 to 2 (on a scale from 1-4).

As geographic background, Gamalama volcano emerges from the sea to form the near-conical 76 km2 Ternate island. The island is situated in the Molucca (Maluku) islands in NE Indonesia about midway between the islands of Borneo and New Guinea (figure 5).

Figure 5. (A) An index map of Indonesia, including the Molucca islands and regional landmarks. Courtesy of U.S. Department of State. (B) A map of the Molucca (Maluku) islands, highlighting Gamalama (Ternate). Courtesy of Indonesia Explore.

Seismicity and eruptions of September 2012. Significant seismicity and other activity at Gamalama remained low from early 2012 until September. During 1-14 September white plumes were sometimes observed rising ~10 m above the crater. When visibility allowed, these plumes were observed from the local obseratory post at Marikuruba and from the W coast of the island, but fog and clouds generally obscured the view.

The telemetered seismograph system (PS-2) recorded deep volcanic earthquakes, shallow volcanic earthquakes, and local tectonic earthquakes, each occurring fewer than five times during 1-14 September. During that same period, there were 63 long-distance tectonic earthquakes and 42 hot air blasts recorded; once they began, signals interpreted as the hot air blasts amounted to 8 occurrences per day. Visual observations and tremor during this time period appeared similar to this volcano’s past behavior.

On 15 September 2012 the following seismic events were recorded: 6 long distance tectonic earthquakes, 9 deep volcanic earthquakes, 2 shallow volcanic earthquakes, 14 hot air blasts accompanied by rumbling sounds, and an interval of tremor began with amplitudes reaching 3-4 mm. Six minutes after the tremor, eruption signals occurred with a maximum amplitude of 40 mm. A phreatic explosion produced ash fall and debris fall. Fog obscured the visibility.

On 16 September 2012, CVGHM reported low-amplitude tremor continuing during 0000-1200 (with 1.5-2.5 mm amplitudes). Medium-to-heavy rain fell at the summit around 1200. At 1358 tremor amplitudes increased to 28 mm, followed 17 min later by a “severe eruption.”

That eruption drove an ash-laden plume to ~1 km above the crater. The plume drifted S and SE (figure 6A), and 5 min later ash fell at the observation post. The Alert Level was raised to 3 and visitors and residents were warned not to come within 2.5 km of the crater. CVGHM suggested that the eruption vented at the same location as those of December 2011.

Figure 6. (A) Photo of the Gamalama eruption on 16 September 2012 viewed from the NW. The ash plume is immediately blown to the S and SE with almost no vertical development. (B) The 17 September 2012 eruption of Gamalama viewed from the ESE. Both photos courtesy of Associated Press and The Jakarta Globe.

An eruption on 17 September 2012 produced a white-and-gray plume that rose 300 m above the crater and drifted E and SE (figure 6B). Ashfall was reported in the S, SE, and E parts of the island.

Calm prevailed for at least a few weeks after the eruption. Seismicity decreased in early October; on 8 October white plumes rose a mere 10-50 m. The Alert Level was lowered to 2 on 9 October, and the resulting exclusionary zone extended 1.5 km from the crater.

Information Contacts: Center for Volcanology and Geological Hazard Mitigation (CVGHM), Jl. Diponegoro 57, Bandung, West Java, Indonesia, 40 122 (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/); The Jakarta Post, Jl. Palmerah Barat 142-143, Jakarta 10270, Indonesia (URL: http://www.thejakartapost.com/); Associated Press (AP), (URL: http://www.apimages.com/); USA Today, 7950 Jones Branch Road, McLean, VA 22102 (URL: http://www.usatoday.com/); BBC News (URL: http://www.bbc.co.uk/); United States Department of State - Bureau of Consular Affairs (URL: http://travel.state.gov/); Indonesia Explore (URL: http://indonesiaexplore.com/).

Index of Weekly Reports


2012: January | September | October
2011: November | December
2008: May
2007: August | October
2003: July | October

Weekly Reports


10 October-16 October 2012

CVGHM reported that eruptions at Gamalama during 15-16 September prompted CVGHM to raise the Alert Level to 3 (on a scale of 1-4) on 16 September. An eruption on 17 September produced a white-and-gray plume that rose 300 m above the crater and drifted E and SE. Ashfall was reported in the ESE part of Ternate (S, SE, and E part of island). After the eruption through 8 October white plumes rose 10-50 m high. Seismicity decreased in early October. The Alert Level was decreased to 2 on 9 October. Visitors and residents were warned not to approach the crater within a radius of 1.5 km.

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


12 September-18 September 2012

CVGHM reported that during 1-14 September cloudy weather and fog at Gamalama mostly prevented observations from the post in Marikurubu and from S Ternate (S, SE, and E part of island); white plumes were sometimes observed rising 10 m above the crater. A phreatic eruption on 15 September at 2027 produced ashfall in Ternate. An eruption at 1415 the next day was accompanied by rumbling sounds. A plume rose 1 km and drifted SE and S, producing ashfall at the Gamalama observation post five minutes later. Neither eruption was observed due to fog. The Alert Level was raised to 3 (on a scale of 1-4) on 16 September. Visitors and residents were warned not to approach the crater within a radius of 2.5 km.

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


25 January-31 January 2012

CVGHM lowered the Alert Level for Gamalama from 3 to 2 (on a scale of 1-4) on 24 January based on visual observations of white plumes rising as high as 100 m above the crater and a decrease in seismicity since the last eruption on 23 December 2011.

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


28 December-3 January 2012

According to news articles, at least three people were killed and 1,000-2,600 more from several villages were displaced by lahars from Gamalama during on 27-28 December. The lahars destroyed many homes in the Tubo and Tofure villages and along the Togorara and Marikurubu rivers. The Alert Level remains at 3 (on a scale from 1-4).

Sources: BBC News; The Jakarta Post


14 December-20 December 2011

Based on a SIGMET and information from the Ujung Pandang City MWO, the Darwin VAAC reported that on 14 December an ash plume from Gamalama rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 140 km S.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)


7 December-13 December 2011

Based on information from CVGHM, the Darwin VAAC reported that during 7-10 December ash plumes from Gamalama rose to altitudes of 2.1-6.1 km (7,000-20,000 ft) a.s.l. and drifted E and SE. The Alert Level for Gamalama remains at 3 (on a scale from 1-4).

Source: Washington Volcanic Ash Advisory Center (VAAC)


30 November-6 December 2011

CVGHM raised the Alert Level for Gamalama from 2 to 3 (on a scale of 1-4) on 4 December based on seismicity and visual observations during 1-4 December. On 1 and 4 December white plumes rose to an altitude of 0.15 km (492 ft) a.s.l. and drifted W. Clouds obscured views on the other days.

Based on information from CVGHM, the Darwin VAAC reported that during 5-6 December ash plumes from Gamalama rose to altitudes of 2.4-3.0 km (8,000-10,000 ft) a.s.l. and drifted SE.

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


7 May-13 May 2008

CVGHM raised the Alert Level for Gamalama to 2 (on a scale of 1-4) on 11 May based on seismicity and visual observations during 10-11 May. On 10 May, white to gray plumes rose to an altitude of 1.8 km (5,900 ft) a.s.l. and drifted N. Residents and tourists were not permitted within 2 km of the summit.

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


10 October-16 October 2007

CVGHM lowered the Alert Level for Gamalama to 1 (on a scale of 1-4) on 9 October based on visual observations of plume altitudes and a decline in seismicity.

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


22 August-28 August 2007

CVGHM raised the Alert Level of Gamalama on 24 August from 1 to 2 (on a scale of 1-4) due to an increase in activity. Prior to 10 August, diffuse white plumes rose to an altitude of 1.8 km (5,900 ft) a.s.l. then increased in altitude to 2 km (6,600 ft) a.s.l. during 10-23 August. On 23 August, white and gray plumes rose to an altitude of 2.1 km (6,900 ft) a.s.l. Concurrent with the increased Alert Level, government officials banned access within a 2-km radius of the active crater.

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


29 October-4 November 2003

Volcanic activity decreased at Gamalama during 6-12 October, leading DVGHM to reduce the Alert Level from 2 to 1 (on a scale of 1-4) on 13 October. During the report period, gas emissions rose to ~50 m above the summit and the number of daily earthquakes decreased to normal levels.

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


30 July-5 August 2003

VSI raised the Alert Level at Gamalama to 3 (on a scale of 1-4) after an explosion on 31 July around 1430 produced an ash column that rose 0.5-1 km above the volcano and drifted E. Another explosion occurred at 1439 that rose to 1-1.5 km above the volcano, and deposited ash in the town of Ternate ~30 km N of the volcano. The next large explosion occurred at 1625 and ejected incandescent material, produced an ash column that reached 1-2 km above the summit and drifted E, and was accompanied by a pyroclastic flow that traveled ~1 km into the Togorara Valley. VSI raised the Alert Level to 4, the highest level, and some residents near the volcano were evacuated. After an explosion at 1704 produced an ash cloud to 1-1.5 km above the volcano, low-level ash and gas emissions occurred at Gamalama through 1 August.

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


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.

08/1980 (SEAN 05:08) Strong tephra eruption; 40,000 evacuate

09/1980 (SEAN 05:09) Explosions from two craters; evacuees return

07/1983 (SEAN 08:07) Ash ejection; several thousand evacuated

02/1988 (SEAN 13:02) Widespread ashfall; evacuations

03/1988 (SEAN 13:03) Dark plumes; frequent earthquakes

05/1988 (SEAN 13:05) Tremor and deeper earthquakes; gas emission

07/1989 (SEAN 14:07) Gas emission; crater wall collapse; tremor

04/1990 (BGVN 15:04) Explosive eruption ejects thick reddish column

07/1990 (BGVN 15:07) Strong April explosion ejected incandescent tephra

08/1991 (BGVN 16:08) Explosions eject white clouds

11/1991 (BGVN 16:11) Seismicity increases but no change in surface activity

02/1992 (BGVN 17:02) Increased seismicity

04/1992 (BGVN 17:04) Dense steam emission and earthquakes

05/1993 (BGVN 18:05) Ash eruption; pyroclastic flows

07/1993 (BGVN 18:07) Explosive ash eruptions produce columns to heights of 3,000 m

05/1994 (BGVN 19:05) Update on continuing eruptions and seismicity

07/1994 (BGVN 19:07) Eruptions generate ash cloud to ~5 km altitude and cause ashfall

10/1994 (BGVN 19:10) Explosion sends plume ~300 m above summit

07/2003 (BGVN 28:07) Ashfall from 31 July eruption coats Ternate; pyroclastic flow

09/2003 (BGVN 28:09) Several small ash explosions and gas emission through late September

10/2003 (BGVN 28:10) Small ash explosions August to early October; seismicity normal by mid-October

10/2007 (BGVN 32:10) Plumes accompany August 2007 increase in seismic activity

10/2008 (BGVN 33:10) Emissions increase in May 2008

12/2011 (BGVN 36:12) Eruption on 4 December 2011; lahars kill four and displace thousands

11/2012 (BGVN 37:11) Seismicity precedes small ash-bearing eruptions in September 2012




Bulletin Reports

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


08/1980 (SEAN 05:08) Strong tephra eruption; 40,000 evacuate

An incandescent tephra eruption from the central crater began with an explosion on 4 September at 1430, followed by a second ~ 2 hours later, and others at 0030, 0330, and 1120 the next day. Incandescent material fell 500-750 m from the crater, starting brush and forest fires. Ash fell on the entire island, accumulating to a depth of 10 cm by the second day of the eruption at Ternate City, 7-8 km E of the crater. Ash thicknesses reached 15 cm on some parts of the island, according to AFP.

Two earthquakes were felt by persons remaining on the island on 6 September as the eruption continued. By 7 September, activity had declined. Ash clouds rose ~ 1 km and were blown N by the prevailing wind, keeping ash away from the S half of the island, including Ternate City.

About 40,000 of the approximately 60,000 residents fled Ternate Island for Tidore Island, 5 km to the S, during the first two days of the eruption. No casualties have occurred according to the VSI, AFP, and Reuters, although some of the broadcast press apparently incorrectly reported casualties. A hazard map previously prepared by VSI delineates a danger zone of 33 km2 (population 2,500) in the summit area and an alert zone of 30 km2 on the N, NW, and NE flanks (population 2,500). The S and E parts of the island are considered to be safe by VSI.

Information Contacts: A. Sudradjat, VSI; AFP; Reuters.
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09/1980 (SEAN 05:09) Explosions from two craters; evacuees return

The eruption continued vigorously into late September. Seven explosions were recorded during the first week of activity, 17 the second week, and 15 the third week. Eruption clouds ranged from about 500 m to 1,800 m in height. Bombs fell as much as 1 km away, most heavily to the N and NE. By early October, eruptions had ended, but seismicity continued, with episodes of volcanic tremor lasting up to 4.5 hours. Most evacuees had returned home, but some small villages in the NE sector red zone remained evacuated.

Kompas newspaper reported that a new crater had formed ENE of the summit. Both the summit crater (two vents) and the new crater have ejected incandescent tephra.

Information Contacts: A. Sudradjat and L. Pardyanto, VSI; M. Krafft, Cernay; Kompas, Bandung.
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07/1983 (SEAN 08:07) Ash ejection; several thousand evacuated

AFP reported that an eruption began 9 August. Residents of villages closest to the volcano were awakened at 0445 by the activity. A thick black eruption column containing incandescent material rose 1.5 km and "red-hot lava" moved down the N flank, destroying scores of homes and plantations. Ash fell W of the volcano, closing an airport. Explosions on 10 August at about 1000 and 1200 produced 1.5-km ash columns. A wind shift threatened to cause ashfalls E of Gamalama. Earthquakes centered on the volcano accompanied the eruption.

More than 5,000 persons living near the volcano evacuated to the town of Ternate, capital of North Moluccas regency. No casualties were reported. Despite bad weather, vessels were standing by in case Ternate required evacuation.

Information Contacts: AFP.
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02/1988 (SEAN 13:02) Widespread ashfall; evacuations

Gamalama erupted on 12 February at 1830, spreading ash over a wide area of Ternate Island. No new lava flow accompanied the activity. VSI issued an aircraft advisory on 13 February, warning of potential hazards from the activity. The press reported that police and soldiers had helped evacuate ~ 1,500 residents of villages near Gamalama, added to ~ 2,000 people from the same area who had previously been evacuated to the neighboring island of Halmahera. Details of premonitory activity are limited, but relatively deep earthquakes had been recorded 18-19 January.

Information Contacts: VSI; ANS; UPI.
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03/1988 (SEAN 13:03) Dark plumes; frequent earthquakes

Since the 12 February ash eruption, dark "smoke" has frequently been reported from the crater. Seismic activity continued beneath the volcano, with about five volcanic and 75 deeper ("tectonic") earthquakes daily during March.

Information Contacts: VSI.
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05/1988 (SEAN 13:05) Tremor and deeper earthquakes; gas emission

On 17, 23, and 24 May seismic tremor was recorded for periods of 3-8 minutes. Deeper earthquakes were recorded at a rate of 13/day during late May. White fume was consistently present above the crater, rising more than 400 m above the summit. A plume has probably been emitted intermittently since the 12 February explosive eruption.

Information Contacts: VSI.
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07/1989 (SEAN 14:07) Gas emission; crater wall collapse; tremor

Weak white fumes rose 150-300 m above the crater in late July. Collapse and sliding of the crater walls caused extension of the crater toward the NW and E. Fumarole temperatures at the volcano's summit were 82-90°C. On 28 and 29 July, volcanic tremor episodes with amplitudes of 0.5 mm were recorded for 11 and 16 minutes. Volcanic (16), distant tectonic (420), and local tectonic (10) earthquakes were recorded.

Information Contacts: VSI.
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04/1990 (BGVN 15:04) Explosive eruption ejects thick reddish column

Press reports indicated that an eruption began at 1847 on 25 April, ejecting a thick reddish column ~ 1.5 km high. Authorities inspected areas believed to be at risk from lava flows, but did not immediately order evacuations.

Information Contacts: Jakarta Domestic Service.
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07/1990 (BGVN 15:07) Strong April explosion ejected incandescent tephra

On 25 April a large explosion at 1848 ejected incandescent tephra from the main crater. The ash column reached 2,500-5,000 m above the volcano and deposited material to the W. The main eruptive activity ceased at 1928, but was followed by smaller eruptions producing ash columns to 1,500 m. A flow, suspected to be a nuée ardente, traveled 4.5 km from the crater, leaving a deposit 5 m thick with a maximum temperature of 320°C. No victims and only minor damage were reported. Activity declined to weak emissions of white to grayish-white vapor 300-500 m above the crater by 30 April.

Information Contacts: VSI.
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08/1991 (BGVN 16:08) Explosions eject white clouds

Two strong explosions were seen from Ternate, 6 km ESE of the summit, on 15 June, ejecting mainly white clouds. A 20 June climb revealed only white vapor filling the summit crater.

Information Contacts: V. Clavel and P. Vetsch, SVG, Switzerland.
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11/1991 (BGVN 16:11) Seismicity increases but no change in surface activity

Increased volcanic seismicity was recorded in early December, with the number of events rising from 24/day in the first week to 32/day the second week of the month. Typically, no more than five volcanic earthquakes are recorded daily at Gamalama. Surface activity was limited to low-pressure emission of vapor, rising 100-150 m above the crater rim.

Information Contacts: VSI.
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02/1992 (BGVN 17:02) Increased seismicity

A thin white vapor plume rose 50-100 m above the crater rim in early March, accompanied by an average of 26 volcanic earthquakes/day. Deep volcanic earthquakes increased from 91 during the first week in March to 159 the following week, as the weekly number of shallow volcanic earthquakes grew from 18 to 26.

Information Contacts: W. Modjo and W. Tjetjep, VSI.
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04/1992 (BGVN 17:04) Dense steam emission and earthquakes

Dense steam emissions continued through mid-Apr, rising 50-300 m above the crater rim. Earthquakes averaged 12-13/day in mid-Apr, an increase from early April, but only half the early March rate (17:02).

Information Contacts: W. Modjo, VSI; UPI.
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05/1993 (BGVN 18:05) Ash eruption; pyroclastic flows

A radio broadcast from Indonesia reported an eruption at Gamalama on 21 May [see 18:7]. An earthquake swarm with 67 events preceded the eruption. The report described ash and incandescent ejecta as well as nuees ardentes that traveled W along the paths of lava flows from previous eruptions.

Information Contacts: Jakarta Radio Network.
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07/1993 (BGVN 18:07) Explosive ash eruptions produce columns to heights of 3,000 m

Ash explosions at 0600 and 0625 on 6 May produced eruption columns that rose 2,500 and 2,000 m, respectively, above the summit. There was also a small eruption at 1500 on 8 May. The strongest explosion occurred at 1338-1352 on 12 May, preceded by detonation sounds and incandescent ballistic bombs. A black ash column from this eruption rose 3,000 m and could be seen from the observatory. About 141,000 m3 of material was erupted. There was no damage caused by this eruption. An Indonesian radio broadcast also reported an eruption on 21 May (18:05). A pilot report described a smoke plume at 1000 on 17 August rising ~ 480 m above the rim before drifting NNW and dissipating.

Information Contacts: W. Tjetjep, VSI; J. Lynch, SAB.
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05/1994 (BGVN 19:05) Update on continuing eruptions and seismicity

Following its May 1993 eruption . . . activity remained high. An explosion in January 1994 at the main crater produced a dark ash cloud 750-1,000 m tall. Small gas explosions were common during February 1994, they often rose 200-400 m above the crater. One or more ash eruptions took place 25-27 March, dusting the village of Rua on the volcano's eastern slopes with thin ash.

Tectonic earthquakes were numerous, especially following the Halmahera earthquake of 21 January, 1994. Prior to the earthquake there were typically 10-25 events/day, following it there were 40 events/day. Volcanic earthquakes remained at normal levels, 3-5 events/day.

Information Contacts: W. Tjetjep, VSI; BOM Darwin, Australia; S. Matthews, Univ of Bristol; UPI; Antara News Agency.
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07/1994 (BGVN 19:07) Eruptions generate ash cloud to ~5 km altitude and cause ashfall

A NOTAM that originated from the Ujung Pandang FIR on 6 May 1994 requested that all aircraft avoid the area around Gamalama volcano. VSI did not note any unusual activity on that day, and no ash cloud was detected on satellite imagery. The warning only noted that the height of "dust" was variable.

Members of the SVE visited Gamalama at 1130 on 21 July. Summit activity consisted of violent degassing from the summit crater, producing a white-gray plume above the volcano; no solid material was ejected during the observations. A small active fumarolic area on the W crater rim exhibited yellow sulfur deposits. White vapor was rising from a large crack on the E crater rim, a part of the crater that appeared to be very unstable. The bottom of the crater could not be seen from the rim.

VSI reported that activity from the main crater increased with a sudden eruption on 5 August 1994 at 2125. The eruption produced an ash cloud to a height of 3,000 m above the summit . . . and accompanying ash falls. A felt earthquake a few minutes before the eruption had an intensity of MM II-III. Volcanic tremor recorded since 10 August preceded another eruption at about 2400 on 13 August from the same location. A news report indicated that explosions on 14 August caused ashfall in Ternate (~ 4 km SE), and that 5-20 minor explosions/day had occurred in recent days.

Following eruptions in May 1993 (18:5 & 7; and VSI, 1993a), seismicity steadily decreased to low levels by the end of June; vapor emission stopped by the end of August 1993 (VSI, 1993b). Seismicity began increasing again in December 1993 (VSI, 1993b), and explosions were reported during January-March 1994 (19:05).

Information Contacts: W. Tjetjep, VSI; H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland; BOM Darwin, Australia; AP; Radio Republik Indonesia.
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10/1994 (BGVN 19:10) Explosion sends plume ~300 m above summit

An eruption late on 15 October sent a plume ~ 300 m above the summit . . ., according to news reports. No casualties or damage were reported, although some ash fell in several villages on the slopes of the volcano and the explosion shook buildings.

Information Contacts: Antara News Agency; Reuters.
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07/2003 (BGVN 28:07) Ashfall from 31 July eruption coats Ternate; pyroclastic flow

According to the Volcanological Survey of Indonesia (VSI), at 0300 on 31 July 2003, six type-A volcanic earthquakes were recorded. At 0600 the cloud issuing from the crater became thicker, but the gas pressure remained modest and similar to that normally seen. A series of explosive eruptions that began at 1434 sent a dark gray ash column 500-1,000 m high that drifted E toward Sultan Baabulah airport. A second explosion at 1625 produced a dark-gray ash column with strong gas pressure. The ash column rose 1-2 km above rim and drifted E carrying glowing material.

At 1627 a pyroclastic flow into Togorar valley on the NE flank traveled as much as 1 km but did not reach the village. A continuous blasting sound accompanied a series of ash emissions. Between 1704-1812, a dark gray ash column rose to 1,000-1,500 m, then during 1850-2200 a white-gray ash plume rose to 500 m. Several white gas plumes rose 10-150 m from 2209 through 0600 on 1 August. A steady glow was observed from 0200-0400.

After the initial outbursts, during 0000-1430 on 1 August, seismometers registered seven tectonic earthquakes, 16 shallow volcanic earthquakes, and two deep volcanic earthquakes. Continuous tremor also registered, with a maximum amplitude of 29-30 mm. Ashfall was 1-3 cm thick in the E part of the area, and some of the local population was evacuated.

According to local officials, Ternate (the regional capital, ~7 km E of Gamalama) was covered with thick ash. There were no reports of casualties or damage. The hazard status was set at level 3 starting at 1250 on 31 July and raised to the maximum, level 4, at 0000 the next day.

VSI reported that the last eruption occurred in 1996 from the main crater, followed by a pyroclastic flow to the E.

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/).
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09/2003 (BGVN 28:09) Several small ash explosions and gas emission through late September

An eruptive event on 31 July 2003 at Gamalama produced ashfall and pyroclastic flows (BGVN 28:07). The Volcanological Survey of Indonesia (VSI) report for the week of 28 July-3 August noted that the hazard status was downgraded to Alert Level 3 on 2 August. A white gas plume was reported as rising 10-50 m above the summit and the seismograph record was dominated by emission events.

Volcanic activity was low during 18-31 August, with white gas emissions and several small ash explosions. White-gray ash plumes emitted from the crater reached 100 m high. Night glow was seen just above the crater rim. Recorded emission and tectonic earthquakes averaged four events per day. Reduced activity continued during 1-28 September 2003, again with white gas emission and small ash explosions that occurred several times. Seismicity was dominated by tectonic and emission events (table 1). The hazard status since 18 August has been at Alert Level 2 (on a scale of 1-4).

Table 1. Seismicity at Gamalama during 1-28 September 2003. Courtesy of VSI.

    Date(2003)      Deep      Shallow     Emission    Tectonic
                  Volcanic    Volcanic

    01-07 Sep         1          7           35          64
    08-14 Sep         3          1           16          59
    15-21 Sep         0          1           12          57
    22-28 Sep         0          3           21          49

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/).
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10/2003 (BGVN 28:10) Small ash explosions August to early October; seismicity normal by mid-October

A series of explosive eruptions on 31 July 2003 produced ashfall and pyroclastic flows (BGVN 28:07). Several small ash explosions occurred throughout August and September (BGVN 28:09). Activity was similar during 29 September-5 October 2003, with white gas emissions rising 25-100 m and some small ash explosions. Volcanic seismicity consisted of one deep earthquake, two shallow earthquakes, and 24 emission events. Activity remained low the following week, 6-12 October, with gas emissions rising 25-50 m. The number of daily seismic events this week had returned to normal levels, so the hazard status was downgraded to Alert Level 1 (on a scale of 1-4) on 13 October.

Information Contacts: Dali Ahmad, Hetty Triastuty, Nia Haerani, and Suswati, 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/).
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10/2007 (BGVN 32:10) Plumes accompany August 2007 increase in seismic activity

On 24 August 2007, the Center of Volcanology and Geological Hazard Mitigation (CVGHM) raised the Alert Level of Gamalama from 1 to 2 (on a scale of 1-4) due to an increase in seismic activity beginning 20 August. Prior to 10 August, diffuse white plumes rose to an altitude of 1.8 km, then increased in altitude to 2 km during 10-23 August. On 23 August, white and gray plumes rose to an altitude of 2.1 km. Concurrent with the increased Alert Level, government officials banned access within a 2-km radius of the active crater. No thermal anomalies were measured by MODIS satellites during this time. CVGHM lowered the Alert Level to 1 on 9 October 2007, based on visual observations of plume altitudes and a decline in seismicity.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://portal.vsi.esdm.go.id/joomla/).
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10/2008 (BGVN 33:10) Emissions increase in May 2008

On 11 May 2008, CVGHM reported that emissions from Gamalama had risen to higher altitudes during the previous two days. On 10 May, white-to-gray plumes rose to an altitude of 1.8 km and drifted N. On 11 May, white plumes increased throughout the day from 1.7 to 2.2 km altitude. Based on the visual observations and seismicity, CVGHM raised the Alert Level and warned residents and tourists not to go within 2 km of the summit. No thermal anomalies were measured by MODIS during this time.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://portal.vsi.esdm.go.id/joomla/).
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12/2011 (BGVN 36:12) Eruption on 4 December 2011; lahars kill four and displace thousands

Gamalama volcano, Indonesia, erupted on 4 December 2011, following precursory gas emissions and an increase in seismicity. Lahars killed at least four people, injured dozens, and thousands evacuated. Gamalama had remained at Alert Level 2 (on a scale from 1-4) since 11 May 2008 (BGVN 33:10). Coincident with the beginning of the eruption at 2300 on 4 December, CVGHM raised the Alert Level from 2 to 3, prohibiting access to areas within 2.5 km of the summit. In late January seismicity stabilized and the hazard status fell.

Precursory activity. The Center for Volcanology and Geological Hazard Mitigation (CVGHM) reported white plumes reaching 25 and 150 m above the summit of Gamalama on 1 and 4 December, respectively (figure 1). Clouds obscured the view on 2-3 December. Seismicity also increased during 1-4 December, with a sharp increase in the occurrence of shallow volcanic earthquakes, from one on 3 December to 47 on 4 December (table 2). Tremor was recorded continuously after 2258 on 4 December. At 2300, the Alert Level was raised to 3, and access to Hazard Zone II (areas within 2.5 km of the summit) was prohibited.

Figure 1. Reported plume heights at Gamalama during 1-14 December 2011. No plumes were reported by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) or the Darwin Volcanic Ash Advisory Centre (VAAC) on 2-3 and 10-12 December. Plumes heights indicated in white were ash-free emissions, while those in black indicate plumes that contained ash. The Alert Level was raised from 2 (yellow) to 3 (orange) at 2300 on 4 December. Data courtesy of CVGHM and Darwin VAAC.

Table 2. Precursory seismicity during 1-4 December 2011 at Gamalama. Note the sharp increase of shallow volcanic earthquakes on 4 December 2011; that day, tremor amplitude also increased by at least an order of magnitude. The symbol ’-’ indicates data not reported. Data courtesy of CVGHM.

  Seismicity        1 Dec 2011      2 Dec 2011      3 Dec 2011      4 Dec 2011

Shallow volcanic         -              -                1              47
Deep volcanic            -              1                -               5
Local tectonic           2              -                3               2
Distant tectonic         1             15                2               8
Hot air blasts           2              5                3               5
Tremor amplitude    0.5-1.5 mm          -                -          up to 35 mm
Teleseismic              -              -                2               -

Eruption. According to the Jakarta Post, most residents living on Gamalama’s slopes evacuated, although some insisted on staying in their homes. Most of Ternate and its surrounding villages were covered in ash (figure 2), and ash fall caused the loss of electricity in some areas around the slopes of the volcano. No fatalities were reported.

Figure 2. Residents in the Tubo district (3-4 km from the summit) walking on recently deposited (and most likely reworked) volcanic material that fell or was remobilized after an eruption of Gamalama. Photograph dated 5 December 2011; courtesy of Associated Press.

Over the next 10 days (into mid-December) the Darwin Volcanic Ash Advisory Centre (VAAC) reported ash plumes that rose to 2.1-6.1 km altitude (figures 1 and 4). Some plumes drifted up to 140 km to the S, SE, and E. Three photos of plumes on 12 December appear in figure 3.

Figure 3. Photos of ash-bearing eruptive plumes from Gamalama taken on 12 December 2011. Courtesy of Andi Rosadi, Volcano Discovery.

Fatal lahar. The Jakarta Post reported that heavy rainfall mobilized fresh ash deposits, spawning a lahar on 27 December 2011 that killed at least four people and injured dozens; many homes were destroyed in the Tubo and Tofure districts, and in locations along the Togorara and Marikurubu rivers (figure 4). On 1 January 2012, the Jakarta Post reported that up to 3,490 people were still being housed in ten different emergency shelters. It also reported that the National Disaster Mitigation Agency (Badan Nasional Penanggulangan Bencana, BNPB) had allocated 1.1 billion Indonesian Rupiah (US$121,000) in emergency funds for the residents affected by the eruption. The Jakarta Globe reported that thousands of farmers had their crops destroyed by ash erupted during December 2011. Agricultural losses are especially devastating, as the island has historically been a major producer of spices such as cloves.

Figure 4. Combined Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery of Gamalama (Ternate Island) on 17 April 2005 and 30 November 2006. Ternate City, the districts of Tubo and Tofure, and the Togorara and Marikurubu rivers are indicated. Index map shows regional location. ASTER imagery courtesy of the Geological Survey of Japan; index map modified from MapsOf.net.

Eruption wanes. Following a month of decreasing activity, CVGHM decreased the Alert Level from 3 to 2 on 24 January 2012. The Alert Level notification cited that, since 23 December 2011, seismicity was dominated by tremor with relatively stable amplitude (0.5-2 mm) and hot air blasts that tended to decrease in occurrence (table 3). During the same period, observed plumes from Gamalama reached 25-100 m above the summit, none of which contained observable ash. In consequence of the lowered Alert Level, access to the summit craters of Gamalama was prohibited, and residents living along rivers descending the flanks of the volcano were advised to be aware of the dangers of lahars. In addition, the North Maluku Province Local Government was asked to prepare evacuation procedures in the case of an increase in activity.

Table 3. Seismicity at Gamalama from 24 December 2011 through 23 January 2012. CVGHM lowered the Alert Level from 3-2 on 24 January. Data courtesy of CVGHM.

Seismicity                24-31 Dec 2011     1-8 Jan 2012     8-17 Jan 2012     18-23 Jan 2012
								
Shallow volcanic                9                  2                 6                5
Deep volcanic                   5                  8                 1                5
Local tectonic                  4                  1                 5                5
Distant tectonic               31                 16                39               45
Hot air blasts (per day)       50                 73                28               30
Tremor amplitude            0.5-2 mm          0.5-1.5 mm         0.5-1 mm         0.5-1 mm

Information Contacts: Center for Volcanology and Geological Hazard Mitigation (CVGHM), Jl. Diponegoro 57, Bandung, West Java, Indonesia, 40 122 (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/); The Jakarta Post, Jl. Palmerah Barat 142-143, Jakarta 10270, Indonesia (URL: http://www.thejakartapost.com/); Associated Press (AP), (URL: http://www.apimages.com/); Andi Rosadi, Volcano Discovery (URL: http://www.volcanodiscovery.com/); Erik Klemetti/Wired (URL: http://www.wired.com/wiredscience/eruptions); Geological Survey of Japan (URL: http://www.gsj.jp/); MapsOf.net (URL: http://mapsof.net/); The Jarkarta Globe, Citra Graha Building, 11th Floor, Suite 1102, Jl. Jend. Gatot Subroto Kav 35-36, Jakarta 12950, Indonesia (URL: http://www.thejakartaglobe.com/).
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11/2012 (BGVN 37:11) Seismicity precedes small ash-bearing eruptions in September 2012

This report discusses a series of small but punctuated eruptions on 15-17 September 2012 associated with the return of seismicity at Gamalama. Fog obscured visibility but ash fell on inhabited areas. The eruptions were judged similar to those seen 4 December 2011 (BGVN 36:12).

As we noted previously, heavy rains after the 4 December 2011 eruptions led to lahars on 27-28 December that killed four people, injured dozens, and displaced thousands (BGVN 36:12). Photos showed that these lahars had carried many meter-diameter blocks into inhabited areas on the lower flanks. Videos from helicopter flights confirmed that in the upslope region, chutes and drainages had also fed finer ash into the lahars.

According to the Center for Volcanology and Geological Hazard Mitigation (CVGHM), on 24 January 2012, after witnessing an interval of generally reduced seismicity, an absence of significant ash-bearing plumes, and weak steam plumes rising only ~100 m above the summit, they lowered the Alert Level from 3 to 2 (on a scale from 1-4).

As geographic background, Gamalama volcano emerges from the sea to form the near-conical 76 km2 Ternate island. The island is situated in the Molucca (Maluku) islands in NE Indonesia about midway between the islands of Borneo and New Guinea (figure 5).

Figure 5. (A) An index map of Indonesia, including the Molucca islands and regional landmarks. Courtesy of U.S. Department of State. (B) A map of the Molucca (Maluku) islands, highlighting Gamalama (Ternate). Courtesy of Indonesia Explore.

Seismicity and eruptions of September 2012. Significant seismicity and other activity at Gamalama remained low from early 2012 until September. During 1-14 September white plumes were sometimes observed rising ~10 m above the crater. When visibility allowed, these plumes were observed from the local obseratory post at Marikuruba and from the W coast of the island, but fog and clouds generally obscured the view.

The telemetered seismograph system (PS-2) recorded deep volcanic earthquakes, shallow volcanic earthquakes, and local tectonic earthquakes, each occurring fewer than five times during 1-14 September. During that same period, there were 63 long-distance tectonic earthquakes and 42 hot air blasts recorded; once they began, signals interpreted as the hot air blasts amounted to 8 occurrences per day. Visual observations and tremor during this time period appeared similar to this volcano’s past behavior.

On 15 September 2012 the following seismic events were recorded: 6 long distance tectonic earthquakes, 9 deep volcanic earthquakes, 2 shallow volcanic earthquakes, 14 hot air blasts accompanied by rumbling sounds, and an interval of tremor began with amplitudes reaching 3-4 mm. Six minutes after the tremor, eruption signals occurred with a maximum amplitude of 40 mm. A phreatic explosion produced ash fall and debris fall. Fog obscured the visibility.

On 16 September 2012, CVGHM reported low-amplitude tremor continuing during 0000-1200 (with 1.5-2.5 mm amplitudes). Medium-to-heavy rain fell at the summit around 1200. At 1358 tremor amplitudes increased to 28 mm, followed 17 min later by a “severe eruption.”

That eruption drove an ash-laden plume to ~1 km above the crater. The plume drifted S and SE (figure 6A), and 5 min later ash fell at the observation post. The Alert Level was raised to 3 and visitors and residents were warned not to come within 2.5 km of the crater. CVGHM suggested that the eruption vented at the same location as those of December 2011.

Figure 6. (A) Photo of the Gamalama eruption on 16 September 2012 viewed from the NW. The ash plume is immediately blown to the S and SE with almost no vertical development. (B) The 17 September 2012 eruption of Gamalama viewed from the ESE. Both photos courtesy of Associated Press and The Jakarta Globe.

An eruption on 17 September 2012 produced a white-and-gray plume that rose 300 m above the crater and drifted E and SE (figure 6B). Ashfall was reported in the S, SE, and E parts of the island.

Calm prevailed for at least a few weeks after the eruption. Seismicity decreased in early October; on 8 October white plumes rose a mere 10-50 m. The Alert Level was lowered to 2 on 9 October, and the resulting exclusionary zone extended 1.5 km from the crater.

Information Contacts: Center for Volcanology and Geological Hazard Mitigation (CVGHM), Jl. Diponegoro 57, Bandung, West Java, Indonesia, 40 122 (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/); The Jakarta Post, Jl. Palmerah Barat 142-143, Jakarta 10270, Indonesia (URL: http://www.thejakartapost.com/); Associated Press (AP), (URL: http://www.apimages.com/); USA Today, 7950 Jones Branch Road, McLean, VA 22102 (URL: http://www.usatoday.com/); BBC News (URL: http://www.bbc.co.uk/); United States Department of State - Bureau of Consular Affairs (URL: http://travel.state.gov/); Indonesia Explore (URL: http://indonesiaexplore.com/).
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Gamalama (Peak of Ternate) is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera and is one of Indonesia's most active volcanoes. The island of Ternate was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the thorough documentation of Gamalama's historical activity. Three cones, progressively younger to the north, form the summit of Gamalama, which reaches 1715 m. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano. Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2012 Sep 15 2012 Sep 17 Confirmed 1 Historical Observations Summit crater
2011 Dec 5 2011 Dec 23 Confirmed 2 Historical Observations
[ 2008 May 10 ] [ Unknown ] Uncertain 1  
[ 2007 Aug 23 ] [ Unknown ] Uncertain 1  
2003 Jul 31 2003 Oct 2 ± 3 days Confirmed 2 Historical Observations
1996 Unknown Confirmed 2 Historical Observations
1994 Jan 1994 Oct 15 (in or after) Confirmed 2 Historical Observations
1993 May 6 1993 May 21 Confirmed 2 Historical Observations
[ 1991 Jun 15 ] [ 1991 Jun 15 ] Uncertain 1  
1990 Apr 25 1990 Apr 26 Confirmed 3 Historical Observations
1988 Feb 12 1988 Mar (?) Confirmed 2 Historical Observations
1983 Aug 9 1983 Aug 12 Confirmed 3 Historical Observations
1980 Sep 4 1980 Sep 23 Confirmed 2 Historical Observations
1962 Dec 31 1963 Jan 2 (?) Confirmed 2 Historical Observations East flank
1938 Sep 8 1938 Sep 8 Confirmed 2 Historical Observations
1933 Nov 12 Unknown Confirmed 2 Historical Observations
1932 Nov 10 1932 Nov 13 Confirmed 2 Historical Observations
1923 Apr 13 1923 May 6 Confirmed 2 Historical Observations
1918 Aug 1918 Sep 4 Confirmed 1 Historical Observations
1911 Sep 2 1911 Sep 6 Confirmed 1 Historical Observations
1907 Nov 17 1907 Nov 20 Confirmed 2 Historical Observations
[ 1900 May ] [ 1900 Jun 4 ± 4 days ] Uncertain 1  
1898 May 14 1898 May 28 (?) Confirmed 2 Historical Observations
1897 Sep 7 1897 Sep 24 Confirmed 1 Historical Observations
[ 1896 Aug 3 ] [ 1896 Aug 4 (?) ] Uncertain 1  
1895 Dec 19 1895 Dec 19 Confirmed 1 Historical Observations
[ 1884 Dec 8 ] [ 1884 Dec 9 (?) ] Uncertain 1  
1884 May 1884 May Confirmed 2 Historical Observations
1871 Aug 7 1871 Sep 25 Confirmed 2 Historical Observations
[ 1870 ] [ Unknown ] Discredited    
1868 Nov 13 1869 Feb 10 Confirmed 2 Historical Observations
1868 Mar 13 1868 Mar 13 Confirmed 1 Historical Observations
1864 Dec 27 1865 Jan 2 Confirmed 2 Historical Observations
[ 1864 Jun 4 ± 4 days ] [ 1864 Jun 25 ± 5 days ] Uncertain 1  
1864 Jan 20 1864 Feb 17 Confirmed 2 Historical Observations
[ 1863 May 1 (?) ] [ 1863 Jun (?) ] Uncertain 2  
1862 Jul 15 1862 Oct Confirmed 2 Historical Observations
[ 1860 Jun ] [ Unknown ] Uncertain 1  
[ 1858 Nov ] [ 1859 Sep ] Uncertain 1  
1849 Nov 27 1850 Nov 19 Confirmed 2 Historical Observations
1847 Sep 7 1847 Sep 7 Confirmed   Historical Observations
1847 Feb 7 1847 Feb 7 Confirmed 2 Historical Observations
1846 May 19 1846 May 19 Confirmed 2 Historical Observations
[ 1845 Apr 23 ] [ 1845 Sep 3 ] Uncertain 1  
[ 1844 Mar 24 ] [ 1844 Nov 14 ] Uncertain 1  
1843 Apr 10 1843 May 27 Confirmed 2 Historical Observations
1842 Oct 6 1842 Dec 31 Confirmed 1 Historical Observations
[ 1841 Mar 30 ] [ 1841 Nov 20 ] Uncertain 1  
1840 Feb 2 1840 Sep 29 Confirmed 3 Historical Observations
1839 Jan 29 1839 Mar 26 Confirmed 2 Historical Observations
1838 Feb 26 1838 May Confirmed 2 Historical Observations
1835 Jan 4 Unknown Confirmed 2 Historical Observations
1833 Jun 15 Unknown Confirmed 2 Historical Observations
1831 May 27 1831 Jun 27 Confirmed 2 Historical Observations
[ 1830 ] [ Unknown ] Uncertain    
[ 1821 Aug 22 ] [ Unknown ] Uncertain 1  
[ 1815 ] [ Unknown ] Discredited    
1814 Nov 27 1814 Nov 28 Confirmed 2 Historical Observations
1812 Sep 7 1812 Sep 7 Confirmed 2 Historical Observations
1811 Feb 1 1811 May Confirmed 2 Historical Observations
[ 1781 ] [ Unknown ] Uncertain    
1775 Aug 20 1775 Nov 6 Confirmed 3 Historical Observations Summit and NW flank (100 m)
1773 Oct 21 1774 Jan 22 Confirmed 2 Historical Observations
1773 Feb 2 1773 Feb 7 Confirmed 2 Historical Observations
1771 Aug 28 1772 Oct 9 Confirmed 3 Historical Observations
1770 Jul 6 1770 Dec 9 Confirmed 3 Historical Observations
1763 Unknown Confirmed 2 Historical Observations North flank
1739 Unknown Confirmed 2 Historical Observations
1737 Mar 10 1737 Mar 13 Confirmed 2 Historical Observations
1687 May 10 1687 May 11 Confirmed 3 Historical Observations
1686 Sep (?) 1686 Oct 13 (in or after) Confirmed 2 Historical Observations
1676 Dec 31 ± 365 days Unknown Confirmed 2 Historical Observations
[ 1673 Aug 12 ] [ Unknown ] Discredited    
1659 Jun Unknown Confirmed 2 Historical Observations
1653 Dec 31 ± 365 days Unknown Confirmed 3 Historical Observations
1648 Jun 15 1648 Jun 18 Confirmed 2 Historical Observations
[ 1643 Jun 15 ] [ Unknown ] Uncertain 2  
1635 Mar 29 Unknown Confirmed 2 Historical Observations
1608 Jul 18 1608 Jul 19 Confirmed 3 Historical Observations
1605 May Unknown Confirmed 2 Historical Observations
1561 Dec 31 ± 365 days Unknown Confirmed 2 Historical Observations
1538 Unknown Confirmed 3 Historical Observations
1510 ± 10 years Unknown Confirmed 3 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

Ternate | Arufat | Arfat

Cones

Feature Name Feature Type Elevation Latitude Longitude
Keramat, Bukit
    Madiena, Bukit
Cone
Melayu, Bukit
    Kekau, Gunung
Cone

Craters

Feature Name Feature Type Elevation Latitude Longitude
Laguna Crater 75 m
Tolire Jaha
    Tolire Djaha
    Sulla Tacomi
Crater 80 m
Tolire Kecil
    Tolire Ketjil
Crater 10 m
A small explosive eruption of Gamalama volcano in September 1980 is seen from the airport on the NE side of Ternate Island. Nearly 40,000 persons evacuated to a nearby island during the first two days of the eruption, which began on September 4 and lasted until the 23rd.

Photo by S.R. Wittiri, 1980 (Volcanological Survey of Indonesia).
The blocky Batu Angus lava flow traveled from the summit down the northern flank to the sea during an eruption from March 10-13, 1737. The lava flow forms the irregular northern tip of Ternate Island.

Photo by Ruska Hadian, 1994 (Volcanological Survey of Indonesia).
Tolire Jaha maar on the lower NW flank formed during a violent eruption in 1775. The eruption began with explosive activity at the summit on August 20. On the night of September 5-6, a devastating base surge accompanying formation of the maar was responsible for most of the 141 persons that were killed during the eruption. The steep-walled maar is 700 m wide. A smaller maar, Tolire Kecil, formed to the NW along the coast during the same eruption.

Photo by Ruska Hadian, 1994 (Volcanological Survey of Indonesia).
Gamalama volcano (also known as the Peak of Ternate), one of the most active volcanoes of Indonesia, forms Ternate Island off the western coast of Halmahera. The northern and youngest of three cones forming the summit of Gamalama is seen here from the NE. Unvegetated areas in this 1994 photo consist of the ejecta blanket from recent explosive eruptions. Frequent eruptions have occurred since the 16th century, most of which originated from the summit vent.

Photo by Gatot Sugiharto, 1994 (Volcanological Survey of Indonesia).
Gamalama (Peak of Ternate) is a near-conical stratovolcano that rises abruptly NW of the city of Ternate, the principal port of the renowned spice islands of northern Maluku. Three cones, progressively younger to the north, form the summit of Gamalama. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano. Eruptions from Gamalama, one of the most active volcanoes in Indonesia, have been recorded since the 16th century.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).
The three craters forming the summit of Gamalama volcano are visible in this view from the NE flank. The craters have migrated to the north, with the modern cone (right) forming the present summit of the volcano. The prominent shadow cutting diagonally to the right marks the rim of the older GI crater, inside of which the GII cone and crater grew. The GIII crater truncates the flat-topped summit of Gamalama.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).
This classic breadcrust bomb was one of many large volcanic bombs ejected during the September 1980 eruption of Gamalama volcano. Ejected bombs and blocks covered a broad area up to about 1 km from the summit vent, primarily in northern and western directions. The largest ejected block was about 6 m in diameter. The western coast of Halmahera Island is visible in the distance.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).
The flat, grooved surface of this lava block was sandblasted by high-velocity pyroclastic surges during an eruption in 1775. The pyroclastic surges accompanied formation of the 700-m-wide Tolire Jaha maar on the NW flank of Gamalama.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).
The Tidore volcanic complex rises to the south across a narrow strait from Ternate Island in the foreground. The small conical island is Maitara; in the background, its summit hidden in the clouds over southern Tidore Island, is symmetrical Kiematabu peak, the highest mountain in the northern Maluku Islands. Sabale volcano, a truncated caldera at the NE end of Tidore Island, is obscured behind the leaves at the upper left. The lake-filled crater in the foreground is Laguna maar on the southern flank of Gamalama volcano.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).
An aerial view from the north shows the steep-walled Tolire Jaha maar and the smaller Tolire Kecil maar, the small lake immediately adjacent to the shoreline. The two maars were formed during a violent eruption in 1775. The eruption began with explosive activity at the summit on August 20. On the night of September 5-6 a devastating base surge accompanying formation of the 700-m-wide maar was responsible for most of the 141 persons that were killed during the eruption. The eruption ended with renewed NW-flank explosions November 5-6.

Photo by Jack Lockwood, 1980 (U.S. Geological Survey).

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.

Apandi T, Sudana D, 1980. Geologic map of the Ternate quadrangle, north Maluku. Geol Res Devel Centre Indonesia, 1:250,000 scale map and 9 p text.

Bronto S, Hadisantono R D, Lockwood J P, 1982. Geologic map of Gamalama volcano, Ternate, North Maluku. Volc Surv Indonesia, 1:25,000 geol map.

Gogarten E, 1918. Die Vulkane der Nordlichen Molukken. Zeit Vulk, 2: 1-298.

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

Morris J D, Jezek P A, Hart S R, Gill J B, 1983. The Halmahera Island arc, Molucca Sea collision zone, Indonesia: a geochemical survey. In: Hayes D E (ed) The Tectonic and Geologic Evolution of Southeast Asia Seas and Islands, part 2, {Amer Geophys Union, Geophys Monogr}, 27: 373-387.

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

Sudradjat A, 1977. . (pers. comm.).

Volcano Types

Stratovolcano(es)
Maar(s)

Tectonic Setting

Subduction zone
Oceanic crust (< 15 km)

Rock Types

Major
Andesite / Basaltic Andesite
Minor
Dacite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
103,429
204,820
308,691
536,972

Affiliated Databases

Large Eruptions of Gamalama 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.