Ankaratra Field

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 19.4°S
  • 47.2°E

  • 2644 m
    8672 ft

  • 233015
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Ankaratra Field.

The Global Volcanism Program has no Weekly Reports available for Ankaratra Field.

The Global Volcanism Program has no Bulletin Reports available for Ankaratra Field.

The Ankaratra volcanic field is the most prominent and volcanologically diverse on Madagascar. It covers a 100-km-long area in central Madagascar between Avivonimamo and Antsirabe. Activity at the Ankaratra volcanic massif took place from the Miocene until the very recent Quaternary (Besairie, 1973). Trachytic lava domes were erupted during the initial stage and massive fissure eruptions created a series of tectonic lakes. The latest activity occurred in the southern part of the massif and produced well-preserved strombolian basanitic cinder cones. Vulcanian eruptions formed several lake-filled craters. Hot springs occur at Ranomafana.

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

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

Antsirable

Cones

Feature Name Feature Type Elevation Latitude Longitude
Antsirabe Cone
Betafo Cone
Tritriva Cone
Vohitra Cone

Craters

Feature Name Feature Type Elevation Latitude Longitude
Andraikiba Crater - Cone

Thermal

Feature Name Feature Type Elevation Latitude Longitude
Ranomafana Thermal
The Ankaratra volcanic field in central Madagascar consists of trachytic lava domes, fissure vents, basanitic cinder cones, and maars. The volcanic field is one of the largest on the island and covers a 100-km-long area in central Madagascar. Hot springs occur at Ranomafana. North is to the top in this NASA Landsat image.

NASA Landsat7 image (worldwind.arc.nasa.gov)

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.

Battistini R, 1962. Le massif volcanique de l'Itasy (Madagascar). Annales Geog, 384: 167-178.

Besairie H J, 1973. Precis de geologie Malgache. Annales Geol Madagascar, 36: 1-141.

Volcano Types

Pyroclastic cone(s)
Lava dome(s)

Tectonic Setting

Intraplate
Continental crust (> 25 km)

Rock Types

Major
Trachybasalt / Tephrite Basanite
Foidite
Andesite / Basaltic Andesite
Trachyte / Trachyandesite
Phonolite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
123,192
123,192
413,328
5,184,370

Affiliated Databases

Large Eruptions of Ankaratra Field 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.