La Grille

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 11.47°S
  • 43.33°E

  • 1087 m
    3565 ft

  • 233001
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for La Grille.

The Global Volcanism Program has no Weekly Reports available for La Grille.

The Global Volcanism Program has no Bulletin Reports available for La Grille.

La Grille shield volcano at the northern end of Grand Comore Island (also known as Ngazidja) lacks a summit caldera like its larger and more well-known neighbor to the south, Karthala volcano. The basaltic La Grille volcano also contrasts with Karthala in its abundance of pyroclastic cones up to 800 m in height. The cones were erupted along fissures paralleling the summit ridge, which has an irregular profile and is elongated in a N-S direction, and from radial fissures that reach as far as the coast. Recent lava flows, some perhaps as young as a few hundred years, have reached the sea from fissures on the lower western, northern, and eastern flanks.

The Global Volcanism Program is not aware of any Holocene eruptions from La Grille. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the La Grille page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

The Global Volcanism Program has no synonyms or subfeatures listed for La Grille.

Grand Comore Island in the Indian Ocean NW of Madagascar is formed by two massive shield volcanoes. The more well-known and historically active Karthala volcano at the southern end of the island has a 3 x 4 km summit caldera. Elongated rift zones extend to the NNW and SE; the lower SE rift zone forms the Massif du Badjini, a peninsula at the SE tip of the island (bottom right). The Holocene La Grille volcano forms the northern part of the island. Youthful lava flows from both volcanoes have reached the coast.

NASA Space Shuttle image STS009-39-2516, 1983 (http://eol.jsc.nasa.gov/).
Cloud banks drape the flanks of the massive Karthala shield volcano at the southern end of Grand Comore Island. A pyroclastic cone of La Grille, another massive shield volcano that forms the northern part of the island, lies along the coast in the foreground. Karthala contains a 3 x 4 km summit caldera, and elongated rift zones extend to the NNW and SE from the summit of the Hawaiian-style shield. More than twenty eruptions have been recorded at Karthala since the 19th century, but no historical eruptions are known from La Grille volcano.

Copyrighted photo by Steve and Donna O'Meara, 2002.
Pyroclastic cones drape the eastern flanks of La Grille shield volcano at the northern end of Grand Comore Island (also known as Ngazidja). La Grille contrasts with its larger and more well-known neighbor to the south, Karthala volcano, in its lack of a summit caldera and in its abundance of pyroclastic cones up to 800 m in height. Recent lava flows, some perhaps as young as a few hundred years, have reached the sea from fissures on the lower western, northern, and eastern flanks of La Grille.

Copyrighted photo by Steve and Donna O'Meara, 2002.

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.

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.

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

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

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.

Volcano Types

Shield
Pyroclastic cone(s)

Tectonic Setting

Intraplate
Oceanic crust (< 15 km)

Rock Types

Major
Trachybasalt / Tephrite Basanite
Basalt / Picro-Basalt

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
154,373
154,373
243,474
371,795

Affiliated Databases

Large Eruptions of La Grille 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.