Karthala

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 11.75°S
  • 43.38°E

  • 2361 m
    7744 ft

  • 233010
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

9 May-15 May 2012

Observers in the villages of Mde and Mkazi, on the W flank of Karthala, reported increased incandescence from the summit during the night of 9-10 May.

Source: Michael Zorick (Comoros Officer, Embassy of the United States of America)



 Available Weekly Reports


2012: May
2007: January
2006: May
2005: April | November
2003: August


9 May-15 May 2012

Observers in the villages of Mde and Mkazi, on the W flank of Karthala, reported increased incandescence from the summit during the night of 9-10 May.

Source: Michael Zorick (Comoros Officer, Embassy of the United States of America)


10 January-16 January 2007

According to news articles, scientists from the Karthala Volcano Observatory reported that an eruption occurred at Karthala during the evening of 12 January. Residents reported incandescence at the summit and strong fumes. Several strong tremors and earthquakes occasionally larger than M 4 were registered on 13 January. A lava lake that formed in the volcano's crater was seen during aerial observations on 15 January.

Sources: UN Office for the Coordination of Humanitarian Affairs (OCHA), Reuters


31 May-6 June 2006

According to news articles, eruptive activity at Karthala that occurred on 28 May had ceased. No seismic activity was detected during 31 May to 1 June.

Sources: Reuters, Agence France-Presse (AFP)


24 May-30 May 2006

According to the Toulouse VAAC, the Meteorology Office and Observatory of Comores reported an eruption of Karthala of gas and steam on 28 May at about 2105. During 28-29 May from 2300 to 0930, a thin sulfur-dioxide plume extending 60 km NW was visible on satellite imagery. On 29 May, at about 0830, volcanologists flew above the crater and confirmed that only steam and sulfur dioxide had been emitted. According to a news article, a lava lake fed by a central fountain was also observed.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC), Reuters


23 November-29 November 2005

According to news reports, a phreatomagmatic eruption occurred at Karthala during the evening of 24 November. Ash fell in several towns, including in the capital city Morini along the Grand Comore island's SW coast and on the volcano's W flank. According to a UN OCHA report, local authorities estimated that about 2,000 people temporarily fled their villages in the region of Bamboa in the central part of Grand Comore Island, and sought refuge in less exposed areas, such as Mitsamiouli, Mboudé, and Oichili. During the evacuation, an infant died due to respiratory distress. Ashfall caused the closure of shops and schools in Moroni and security forces cleaned the streets using water tankers. Residents were warned to avoid inhaling ash. Preliminary assessments revealed that about 118,000 people living in 75 villages may have been affected by the contamination of domestic water tanks. This is of particular concern because it is the height of the dry season. A UN worker reported that 245,000 people live in the area exposed to ash and estimated that 175,000 could face water shortages. There were also concerns about the impact of ash on agriculture and livestock.

The Toulouse VAAC reported that ash from the early phase of the eruption was not immediately seen on satellite imagery, but that ash fell at the local airport. AFWA reported that the ash cloud was visible on satellite imagery on 25 November at a height of ~11.6 km (~38,000 ft) a.s.l. According to the Karthala Volcano Observatory, a lava lake formed in the volcano's crater. As of 29 November, seismic activity continued at the volcano.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC), UN Office for the Coordination of Humanitarian Affairs (OCHA), IRIN News, US Air Force Weather Agency, Agence France-Presse (AFP)


13 November-19 November 2005

According to news reports, a phreatomagmatic eruption occurred at Karthala during the evening of 24 November. Ash fell in several towns, including in the capital city Morini along the Grand Comore island's SW coast and on the volcano's W flank. According to a UN OCHA report, local authorities estimated that about 2,000 people temporarily fled their villages in the region of Bamboa in the central part of Grand Comore Island, and sought refuge in less exposed areas, such as Mitsamiouli, Mboudé, and Oichili. During the evacuation, an infant died due to respiratory distress. Ashfall caused the closure of shops and schools in Moroni and security forces cleaned the streets using water tankers. Residents were warned to avoid inhaling ash. Preliminary assessments revealed that about 118,000 people living in 75 villages may have been affected by the contamination of domestic water tanks. This is of particular concern because it is the height of the dry season. A UN worker reported that 245,000 people live in the area exposed to ash and estimated that 175,000 could face water shortages. There were also concerns about the impact of ash on agriculture and livestock.

The Toulouse VAAC reported that ash from the early phase of the eruption was not immediately seen on satellite imagery, but that ash fell at the local airport. AFWA reported that the ash cloud was visible on satellite imagery on 25 November at a height of ~11.6 km (~38,000 ft) a.s.l. According to the Karthala Volcano Observatory, a lava lake formed in the volcano's crater. As of 29 November, seismic activity continued at the volcano.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC), UN Office for the Coordination of Humanitarian Affairs (OCHA), IRIN News, US Air Force Weather Agency, News 24


13 April-19 April 2005

According to news articles, eruptive activity at Karthala beginning on 17 April consisted of heightened seismicity, and gas and ash emissions. Hundreds of villagers who lived near the volcano evacuated. Flights to the island were cancelled. Scientists found that lava was confined to the bottom of the summit crater. Activity subsided around 19 April, with ash emissions ceasing. On the 19th, residents began to return to their homes and flights to the island resumed.

Prior to the activity, scientists at the Mount Karthala Observatory reportedly recorded a "seismic crisis" on 24 March, consisting of 40 small earthquakes in comparison to the normal 15 earthquakes per day.

Sources: Agence France-Presse (AFP), Reuters, Agence France-Presse (AFP)


27 August-2 September 2003

Reports of a stream of lava flowing from Karthala towards towns on 30 August were false. Authorities stated that only fume was emitted from cracks on the volcano.

Source: Agence France-Presse (AFP)


20 August-26 August 2003

According to news reports, Observatoire Volcanologique du Karthala scientists noted a steady increase in seismicity at Karthala over the past 3 months. Around 100 earthquakes occurred per day in August in comparison to 1-2 per day in June.

Sources: Reuters, Agence France-Presse (AFP)


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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2007 Jan 12 2007 Jan 15 (?) Confirmed 2 Historical Observations Chahalé crater
2006 May 28 2006 Jun 3 (?) Confirmed 0 Historical Observations Chahalé crater
2005 Nov 24 2005 Dec 8 Confirmed 3 Historical Observations Chahalé crater
2005 Apr 16 2005 Apr 18 Confirmed 2 Historical Observations Chahalé crater
1991 Jul 11 1991 Jul 11 Confirmed 2 Historical Observations Choungou-Chahalé (Choungou-Chamadji)
1977 Apr 5 1977 Apr 10 Confirmed 1 Historical Observations SW flank
1972 Sep 8 1972 Oct 5 Confirmed 1 Historical Observations North end of summit crater
1965 Jul 12 1965 Jul 12 Confirmed 2 Historical Observations Between Changomeni & Chahalé Craters
1956 Jun 1 (?) Unknown Confirmed 2 Historical Observations Chahalé crater
1952 Feb 10 (?) 1952 Feb 12 Confirmed 2 Historical Observations Chahalé crater
1948 Apr 22 1948 Jun 16 Confirmed 2 Historical Observations Cheminee Nord (Changomeni)
1928 ± 2 years Unknown Confirmed 1 Historical Observations
1918 Aug 11 1918 Aug 26 Confirmed 3 Historical Observations NE flank, Changomeni, NE Chahalé
1910 Mar 1910 Mar Confirmed 1 Historical Observations North flank (1300 m)
1904 Feb 25 1904 Apr Confirmed 2 Historical Observations North flank (1300 m)
1883 Mar 1884 Confirmed 2 Historical Observations SE flank
1880 Unknown Confirmed 2 Historical Observations SE flank (Badjini Massif)
1876 Unknown Confirmed 0 Historical Observations SE flank (Badjini Massif)
1872 Unknown Confirmed 2 Historical Observations NW flank (Diboini Plateau)
1865 Unknown Confirmed 2 Historical Observations
[ 1862 ] [ Unknown ] Uncertain 2  
1860 Dec 29 Unknown Confirmed 0 Historical Observations SE flank (Badjini Massif, 1200 m)
1859 Unknown Confirmed 2 Historical Observations NW flank (Diboini Plateau fissures)
1858 Unknown Confirmed 2 Historical Observations Upper NE flank (2200 m)
1857 Unknown Confirmed 2 Historical Observations SE flank (Badjini Massif) & summit
1855 Jul 1 ± 30 days Unknown Confirmed 2 Historical Observations SE flank
1850 (?) Unknown Confirmed 0 Historical Observations West-SW flank (400 m)
1848 Unknown Confirmed 0 Historical Observations SE flank
1833 Unknown Confirmed   Historical Observations Summit caldera ?
1830 Unknown Confirmed 2 Historical Observations
1828 May Unknown Confirmed 2 Historical Observations
1821 Dec 31 ± 365 days Unknown Confirmed   Historical Observations
1814 Dec 31 ± 365 days Unknown Confirmed   Historical Observations
1808 Unknown Confirmed   Historical Observations
1050 ± 150 years Unknown Confirmed   Historical Observations

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

Esson J, Flower M F J, Strong D F, Upton B G J, Wadsworth W J, 1970. Geology of the Comores Archipelago. Geol Mag, 107: 549-557.

Katsui Y (ed), 1971. List of the World Active Volcanoes. Volc Soc Japan draft ms, (limited circulation), 160 p.

Krafft M, 1982. L'eruption volcanique du Kartala en Avril 1977 (Grande Comore, Ocean Indien). CR Acad Sci Paris, Ser-II, 294: 753-758.

Krafft M, 1983. Guide des volcans de la Grande Comore. Unpublished manuscript, 101 p.

Neumann van Padang M, 1963a. Arabia and the Indian Ocean. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 16: 1-64.

Savin C, Grasso J-R, Bachelery P, 2005. Seismic signature of a phreatic explosion: hydrofracturing damage at Karthala volcano, Grand Comore Island, Indian Ocean. Bull Volc, 67: 717-731.

Spath A, Le Roex A P, Duncan R A, 1996. The geochemistry of lavas from the Comores Archipelago, western Indian Ocean: petrogenesis and mantle source region characteristics. J Petr, 97: 961-991.

Strong D F, Jacquot C, 1970. The Karthala caldera, Grande Comore. Bull Volc, 34: 663-680.

Volcanological Society of Japan, 1960-96. Bull Volc Eruptions, no 1-33. [Annual reports issued 1 to 3 years after event year, published since 1986 in Bull Volc].

The southernmost and largest of the two shield volcanoes forming Grand Comore Island (also known as Ngazidja Island), Karthala contains a 3 x 4 km summit caldera generated by repeated collapse. Elongated rift zones extend to the NNW and SE from the summit of the Hawaiian-style basaltic shield, which has an asymmetrical profile that is steeper to the south. The lower SE rift zone forms the Massif du Badjini, a peninsula at the SE tip of the island. Historical eruptions have modified the morphology of the compound, irregular summit caldera. More than twenty eruptions have been recorded since the 19th century from both summit and flank vents. Many lava flows have reached the sea on both sides of the island, including during many 19th-century eruptions from the summit caldera and vents on the northern and southern flanks. An 1860 lava flow from the summit caldera traveled ~13 km to the NW, reaching the western coast north of the capital city of Moroni.