Global Volcanism Program

15 June-21 June 2011

CVGHM reported that on 17 June the Alert Level for Egon was lowered to 1 (on a scale of 1-4) because seismicity had decreased and emission heights had been lower since January.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Available Weekly Reports

15 June 2011 Back to Top

CVGHM reported that on 17 June the Alert Level for Egon was lowered to 1 (on a scale of 1-4) because seismicity had decreased and emission heights had been lower since January.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

7 April 2010 Back to Top

CVGHM reported that on 7 April the Alert Level for Egon was raised from 1 to 2 (on a scale of 1-4) due to a marked increase in seismic activity since 28 March. Small steam plumes normally rose 10 m above the crater.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

15 July 2009 Back to Top

CVGHM reported that the Alert Level for Egon was lowered to 1 (on a scale of 1-4) on 16 July due to the continued decrease in earthquake activity since 12 May. Small steam plumes were occasionally visible when the weather was clear.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

7 May 2008 Back to Top

CVGHM reported that plume altitudes and seismicity from Egon decreased during 25 April-10 May. On 12 May, small steam plumes were visible. The Alert Level was lowered from 3 to 2 (on a scale of 1-4).

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

9 April 2008 Back to Top

CVGHM reported that white plumes from Egon continued to rise to an altitude of 1.8 km (5,900 ft) a.s.l. during 4-14 April. A peak in seismicity was reached during 6-7 April and then declined significantly during 7-15 April. On 15 April, a phreatic explosion produced an ash plume that rose to an altitude of 5.7 km (18,700 ft) a.s.l. and drifted about 25 km W, reaching the town of Maumere. A team of emergency personnel in the closest village to the explosion reported that about 600 people evacuated. CVGHM raised the Alert Level to 3 (on a scale of 1-4).

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

2 March 2005 Back to Top

The Darwin VAAC reported that DVGHM reduced the Alert Level at Egon to 3 (on a scale of 1-4) around 8 March. Ash was not visible on satellite imagery during 2-8 March.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC)

23 February 2005 Back to Top

During 25-27 February, ash plumes from Egon rose to low levels above the volcano and seismicity was dominated by shallow volcanic earthquakes. Egon remained at Alert Level 4, the highest hazard status.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

16 February 2005 Back to Top

According to a news report, as of 17 February recent eruptive activity at Egon had prompted the local government to evacuate hundreds of residents living near the volcano.

Sources: The Jakarta Post

9 February 2005 Back to Top

An explosion at Egon on 14 February at 1830 produced a plume to an unknown height. Egon remained at Alert Level 4, the highest level.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

2 February 2005 Back to Top

An eruption at Egon on 6 February at 0103 led DVGHM to raise the Alert Level to 4 (the highest level) on the following day. The eruption was preceded by an increase in tremor, and consisted of the ejection of "glowing lava" and lapilli-sized material deposited on the volcano's S flank. An eruption occurred on 7 February at 1302 that was similar in size to the 6 February eruption. Before and after the 7 February eruption there was a strong scent of sulfur in the villages of Hebing and Hale. One villager was knocked unconscious due to the gas. All of the vegetation along a fissure on the volcano's S flank had died, also indicating that there was a strong gas emission.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

8 September 2004 Back to Top

A news article reported that an eruption at Egon on 13 September produced an ash plume that drifted ~70 km downwind according to an Indonesian volcanologist. No ash was visible on satellite imagery. There were no reports of injuries or deaths. About 2,200 villagers living on the volcano's slopes had been evacuated since July 2004. Many of the evacuees reported experiencing respiratory problems and skin irritation. The airport in the town of Maumere was closed due to up to 1 cm of ash deposited on facilities and equipment.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC) , Associated Press , The Jakarta Post

1 September 2004 Back to Top

Strong volcanic activity at Egon beginning on 3 September led DVGHM to raise the Alert Level from 3 to 4 (on a scale of 1-4) on 4 September. The increase in volcanic activity began on 27 August when plumes rose to ~300 m above the volcano and explosion earthquakes were recorded. This activity prompted DVGHM to raise the Alert Level from 2 to 3. On 3 September an ash plume rose ~1 km above the summit and on 4 September an ash plume rose to ~3 km. As a consequence, all those living in the villages of Baokrengit, Welimwatu, and Natakoli were evacuated. On 6 September, an explosion produced a plume as high as 2.5 km above the volcano that drifted SW. According to a report released by the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), as of 6 September activity at Egon led to the evacuation of 2,100 people. A total of 4,300 were expected to be evacuated.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) , UN Office for the Coordination of Humanitarian Affairs (OCHA)

25 August 2004 Back to Top

According to news articles, increased volcanic activity at Egon on 31 August led people from at least seven villages near the volcano to temporarily evacuate their homes. Local officials feared that about 2,000 people living on the mountainside were at risk. Reportedly, activity decreased after a few hours and most villagers returned home.

Sources: The Jakarta Post , ABC News - Australian Broadcasting Corporation

21 July 2004 Back to Top

According to DVGHM, an eruption began at Egon on 25 July at 2240, consisting of loud rumbling sounds, a strong sulfur scent, and explosions that rose to 1-1.5 km above the summit. A thick, black plume drifted NNW from the volcano. Interpretations of seismic data revealed that the eruption lasted about 2.5 hours. According to the Darwin VAAC, a plume was visible on satellite imagery. DVGHM reported that about 630 residents near Egon self evacuated from the villages of Egon, Nangatobong, and Itoper. According to a news article, about 1,400 people evacuated. At 1500 on 26 July seismographs recorded nearly continuous explosions produced plumes to ~250 m above the volcano.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) , Darwin Volcanic Ash Advisory Centre (VAAC) , Agence France-Presse (AFP)

7 July 2004 Back to Top

During 5-11 July, observers watching Egon volcano saw it emit white plumes of variable density that typically rose 25-75 m above the summit. The seismograph recorded a continuous series of 'emission earthquakes' with amplitudes of 2 mm. Egon's hazard status remained at Alert Level 2 (on a scale of 1-4).

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

30 June 2004 Back to Top

According to news articles, increased volcanic activity began at Egon on 3 July. Ash from an explosion on the night of the 3rd drifted as far W as Maumere, the capital of Flores. About 2,000 residents near the volcano were evacuated. The four villages worst affected were Egon Gahar, Natakoli, Hale, and Hebing. According to DVGHM, two small explosions occurred at Egon, producing ash clouds to heights of ~150 m. Egon was listed at Alert Level 2 (on a scale of 1-4).

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) , The Jakarta Post

4 February 2004 Back to Top

According to a news report, local scientists found that volcanic activity that began with an eruption at Egon on 29 January had significantly decreased around 5 February. More than 1,000 of the ~5,600 residents who were evacuated from near the volcano returned home on the 5th.

Sources: The Jakarta Post

28 January 2004 Back to Top

Volcanic activity began at Egon on 29 January around 0400 when a landslide traveled down the volcano's E crater wall. Around 1700 an explosion produced a black ash cloud to a height of ~750 m above the summit. During 30-31 January, loud noises from the volcano were followed by emissions of gray ash clouds. In addition, there was a strong scent of sulfur every 50-60 minutes. Visual observations on the 31st revealed that a new solfatara tunnel (sulfur-rich fumarole) was created on the S side of the volcano. Small volcanic earthquakes, deep-volcanic earthquakes, and harmonic tremor were recorded. DVGHM put Egon at Alert Level 3 (on a scale of 1-4) beginning on 2 February. The volcano did not previously have an Alert Level. The Darwin VAAC reported that ash was not visible on satellite imagery.

The volcanism at Egon led to the evacuation of residents near the volcano on 29 January. According to a report by the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), local authorities ordered the evacuation of the villages of Hale, Hebing, Egon Gahar, and Natakoli, which were in high-risk areas on the S side of the volcano. By 31 Jan, ~3,900 people had reached Maumere city, ~35 km away. As many as 6,000 people were evacuated by 1 February. At least one death was reported, although it was not clear if it resulted from the volcanic activity, evacuation process, or other causes. According to news reports, many of the evacuees suffered from respiratory problems, dengue fever, malaria, and diarrhea. There were also reports of looting in the evacuated villages.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) , Darwin Volcanic Ash Advisory Centre (VAAC) , UN Office for the Coordination of Humanitarian Affairs (OCHA) , Khaleej Times , The Jakarta Post

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

Start Date	Stop Date	Eruption Certainty	VEI	Evidence	Activity Area or Unit
2008 Apr 15	2008 Apr 28 (?)	Confirmed	2	Historical
2005 Feb 6	2005 Feb 27	Confirmed	1	Historical	Summit and southern flank
2004 Jul 3	2004 Sep 16 (?)	Confirmed	1	Historical
2004 Jan 29	2004 Feb 5 (?)	Confirmed	1	Historical
[ ~~1907 Sep 28~~ ]	[ ~~Unknown~~ ]	Discredited
[ 1888 ]	[ 1892 ]	Uncertain	2

Gunung Egon volcano sits astride the narrow waist of eastern Flores Island. The barren, sparsely vegetated summit region has a 350-m-wide, 200-m-deep crater that sometimes contains a lake. Other small crater lakes occur on the flanks of the 1703-m-high volcano, which is also known as Namang. A lava dome forms the southern 1671-m-high summit. Solfataric activity occurs on the crater wall and rim and on the upper southern flank. Reports of historical eruptive activity prior to explosive eruptions beginning in 2004 were inconclusive. A column of "smoke" was often observed above the summit during 1888-1891 and in 1892. Strong "smoke" emission in 1907 reported by Sapper (1917) was considered by the Catalog of Active Volcanoes of the World (Neumann van Padang, 1951) to be an historical eruption, but Kemmerling (1929) noted that this was likely confused with an eruption on the same date and time from Lewotobi Lakilaki volcano.