Morne Watt

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 15.307°N
  • 61.305°W

  • 1224 m
    4015 ft

  • 360101
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Morne Watt.

The Global Volcanism Program has no Weekly Reports available for Morne Watt.

The Global Volcanism Program has no Bulletin Reports available for Morne Watt.

Morne Watt (Watt Mountain) volcano lies SE of the Trois Piton/Micotrin lava-dome complex in SE Dominica, east of the capital city of Roseau. The two best-known volcanic features on Dominica, the Valley of Desolation and the Boiling Lake thermal areas, lie on the flank of Morne Watt; both are major tourist attractions within the national park on Dominica. Morne Anglais stratovolcano lies 4 km SW of Morne Watt and Grand Soufrière Hills volcano, with dated pyroclastic-flow producing eruptions about 10,000 years ago, lies 3 km to the east. A major eruption from Morne Watt producing pyroclastic flows took place about 1300 years ago. A moderately large phreatic explosion took place at the Valley of Desolation thermal area NE of Morne Watt in 1880, when ash fell over a 4-km-wide sector at the coast, 10 km from the vent. A smaller phreatic explosion occurred in July 1997, when ashfall was confined to the Valley of Desolation area. These mark the only known historical eruptions on the island of Dominica.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1997 Jul 15 1997 Jul 15 Confirmed 1 Historical Observations NE of Watt Mtn (Valley of Desolation)
1880 Jan 4 1880 Jan 4 Confirmed 2 Historical Observations NE of Watt Mtn (Valley of Desolation)
0640 ± 150 years Unknown Confirmed   Radiocarbon (uncorrected) West flank of Morne Watt
0950 BCE ± 300 years Unknown Confirmed   Radiocarbon (uncorrected) NE of Watt Mtn (Valley of Desolation)
1800 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected) NE of Watt Mtn (Valley of Desolation)

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
Watt Mountain


Cones
Feature Name Feature Type Elevation Latitude Longitude
Anglais, Morne Stratovolcano 1123 m 15° 17' 0" N 61° 20' 0" W
Grande Soufrière Hills Stratovolcano 15° 18' 0" N 61° 17' 0" W


Domes
Feature Name Feature Type Elevation Latitude Longitude
John, Morne Dome 15° 17' 0" N 61° 19' 0" W


Thermal
Feature Name Feature Type Elevation Latitude Longitude
Boiling Lake Hot Spring 750 m 15° 19' 0" N 61° 18' 0" W
Desolation, Valley of
    Grand Soufrière
Thermal 790 m 15° 18' 0" N 61° 18' 0" W
Steam rises from Boiling Lake, a geothermal area on the NE flank of Morne Watt volcano. This phreatomagmatic explosion crater is filled by a bubbling lake about 85 x 75 m wide, with a typical depth of about 10-15 m. Both water level and temperature have varied widely during historical time. The lake was almost empty following the 1880 phreatic eruption, and again temporarily almost emptied in December 2004, when water levels dropped 10 m or more below the high-water mark.

Photo by Paul Jackson, 1998 (Seismic Research Unit, University of West Indies).
Fumarolic clouds mark the Valley of Desolation and Boiling Lake thermal areas, NE of Morne Watt (Watt Mountain) volcano in SE Dominica. The Valley of Desolation and the Boiling Lake are major tourist attractions within the national park east of Roseau. A major eruption from Morne Watt produced pyroclastic flows about 930 years ago. The only historical eruptions on the island of Dominica were a moderately large phreatic explosion at the Valley of Desolation thermal area in 1880 and a smaller phreatic explosion in July 1997.

Photo by Paul Jackson, 1998 (Seismic Research Unit, University of West Indies).
Steep-sided Morne Watt, seen here from the NW, is a lava-dome complex surrounded by block-and-ash flow deposits. The 1224-m-high volcano was constructed south of the Wotten Waven caldera and is flanked by Morne Anglais (4 km to the SW) and the Grand Soufrière Hills volcano, 3 km to the east. The renowned Valley of Depression geothermal area cuts the NE flank of Morne Watt and lies out of view to the left.

Photo by Lee Siebert, 2002 (Smithsonian Institution).

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.

Lindsay J M, Smith A L, Roobol M J, Stasiuk M V, 2005b. Dominica. In: Lindsay J M, Robertson R E A, Shepherd J B, Ali S (eds). {Volcanic Hazard Atlas of the Lesser Antilles}, Trinidad and Tobago, Seismic Res Unit, Univ West Indies, p 1-47.

Lindsay J M, Trumbull R B, Siebel W, 2005c. Geochemistry and petrogenesis of late Pleistocene to Recent volcanism in southern Dominica, Lesser Antilles. J Volc Geotherm Res, 148: 253-294.

Robson G R, Tomblin J, 1966. West Indies. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 20: 1-56.

Seismic Research Unit, 2001. Seismo-volcanic activity in Dominica (updated July 11, 2001). Seismic Res Unit, Univ West Indies (http://www.uwiseismic.com/dominica.html).

Shepherd J B, 1989. Eruptions, eruption precursors and related phenomena in the Lesser Antilles. In: Latter J H (ed), {Volcanic Hazards - Assessment and Monitoring}, Berlin: Springer-Verlag, p 292-311.

Shepherd J B, 2001. Volcanoes of the eastern Caribbean: past activity and future hazards. Paper presented at the Workshop on Volcanic and Seismic Hazards in the eastern Caribbean, May 28- June 1, 2001, 57 p.

Volcano Types

Stratovolcano(es)
Lava dome(s)

Tectonic Setting

Subduction zone
Oceanic crust (< 15 km)

Rock Types

Major
Andesite / Basaltic Andesite
Basalt / Picro-Basalt

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
1,818
35,821
63,178
545,352

Affiliated Databases

Large Eruptions of Morne Watt 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.