Graciosa

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 39.02°N
  • 27.97°W

  • 402 m
    1319 ft

  • 382040
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Graciosa.

The Global Volcanism Program has no Weekly Reports available for Graciosa.

The Global Volcanism Program has no Bulletin Reports available for Graciosa.

The SE end of Graciosa, the northernmost of the central Azorean islands, contains a small 0.9 x 1.6 km caldera with active fumaroles. The 402-m-high SE caldera rim is the high point of the small 4 x 8 km island. The caldera has been the source of eruptions producing significant tephra falls, pyroclastic flows, lahars, and lava flows. An important fumarole field is located in a volcanic cave inside the caldera, and a submarine fumarole occurs off the NW coast of Graciosa. Scoria cones erupted along several widely spaced NE-SW-trending fissures fed a youthful lava field that forms the NW end of the island. The most recent eruption from Pico Tomao, NW of the caldera, produced a lava flow that reached the eastern coast NW of the village of Praia.

The Global Volcanism Program is not aware of any Holocene eruptions from Graciosa. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Graciosa 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 Graciosa.

The small 4 x 8 km island of Graciosa is seen in this NASA Space Shuttle image with north to the upper left. Cloud banks partially obscure the SE end of the island, which contains a small 0.9 x 1.6 km caldera with active fumaroles. Scoria cones are found over much of the island, and several widely spaced NE-SW-trending fissures fed a youthful lava field that forms the NW end of the island.

NASA Space Shuttle image ISS004-E-10893, 2002 (http://eol.jsc.nasa.gov/).
The Caldeira area of Graciosa is seen in this aerial view from the SW with the village of Luz at the center of the image. The small, 0.9 x 1.6 km caldera at the SE end of the island contains active fumaroles. The 402-m-high SE caldera rim is the high point of the small 4 x 8 km island. The most recent eruption from Pico Tomao, NW of the caldera, produced a lava flow that reached the eastern coast NW of the village of Praia.

Photo by Angrense, 2007 (Wikimedia Commons).

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.

Mitchell-Thome R C, 1976. Geology of the Middle Atlantic Islands. Berlin: Gebruder Borntraeger, 382 p.

Neumann van Padang M, Richards A F, Machado F, Bravo T, Baker P E, Le Maitre R W, 1967. Atlantic Ocean. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 21: 1-128.

Zbyszewski G, Candido de Medeiros A, Veiga Ferreira O da, Torre de Assuncao C, 1972. Geologic map of Ihla Graciosa (Azores). Servicos Geologicos Portugal, 1:25,000 scale map with 31 p text (in Portuguese).

Volcano Types

Stratovolcano
Caldera
Scoria cone(s)

Tectonic Setting

Rift zone
Oceanic crust (< 15 km)

Rock Types

Major
Basalt / Picro-Basalt
Andesite / Basaltic Andesite
Trachyte / Trachyandesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
2,500
5,941
6,153
96,656

Affiliated Databases

Large Eruptions of Graciosa 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.