Hydrothermal vents and seamounts of the Azores
Encyclopedia
The hydrothermal vents and seamounts of the Azores () are a series of seamount
s which part of the Mid-Atlantic Ridge
and extensive field of hydrothermal vent
s located in the Azores
. Made up of large masses of basalt
typical of mid-ocean regions, these formations, in addition to their geomorphological interest (as rich deposits of ore
s), are homes to a rich biodiversity of plant and animal life on Earth
. They contain food chain
s whose primary production is purely chemosynthetic
, independent of sunlight, and photosynthesis
.
recognizes these efforts, awarding the Azorean regional government with the honorific "Gift to the Earth" prize for their contribution to the preservation of these marine ecosystems. The Azores have an extensive marine area with a variety of seamounts and submarine volcano
es, representing the highest peaks of a complex chain of seamounts located in the Mid-Atlantic Ridge that are home to a diverse group of living creatures.
The isolated Dom João de Castro Bank
, located between São Miguel
and Terceira
, is one such seamount included in this group. The hydrothermal vents located near it provide a good place to study the creatures that live in volcanic habitats.
The Azores also provide a good place to study deep-ocean hydrothermal vents. Deep-ocean hydrothermal vents, situated along the Mid-Atlantic Ridge, have been the target of various investigative projects by many types of scientists. Recently, some interesting communities of living creatures were discovered in the "Lucky Strike" and in the "Menez Gwen" hydrothermal fields, both located in the Azores Exclusive Economic Zone
.
"Lucky Strike" is the largest known hydrothermal field, with 21 active vents spread over 150 km2 (57.9 mi2). The hydrothermal fluids reach temperatures of 330°C (626°F), very close to the boiling point corresponding to the force of pressure at 1,100 m (3,609 ft). The field's fauna is bio-geographically distinct from that of other hydrothermal fields, predominately rich in mussel
s and associated species.
The "Menez Gwen" hydrothermal field is characterized by a 700 m (2,297 ft) volcano
with a diameter of 17 km (10.6 mi). The hydrothermal fluids, with temperatures close to 280°C (536°F), emerge from various active vents at a depth of 850 m (2,789 ft). Large quantities of mussels cover the vents, and are accompanied by shrimp
s, crab
s, and many other species.
Seamount
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of depth. They are defined by oceanographers as...
s which part of the Mid-Atlantic Ridge
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South...
and extensive field of hydrothermal vent
Hydrothermal vent
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both...
s located in the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
. Made up of large masses of basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
typical of mid-ocean regions, these formations, in addition to their geomorphological interest (as rich deposits of ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
s), are homes to a rich biodiversity of plant and animal life on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. They contain food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
s whose primary production is purely chemosynthetic
Chemosynthesis
In biochemistry, chemosynthesis is the biological conversion of one or more carbon molecules and nutrients into organic matter using the oxidation of inorganic molecules or methane as a source of energy, rather than sunlight, as in photosynthesis...
, independent of sunlight, and photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
.
Description
Efforts are being made to classify these areas as protected marine areas under the Convention for the Protection of the North Mid-Atlantic (OSPAR Convention) and in accordance with the requirements of the Habitats Directive. The World Wildlife FundWorld Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...
recognizes these efforts, awarding the Azorean regional government with the honorific "Gift to the Earth" prize for their contribution to the preservation of these marine ecosystems. The Azores have an extensive marine area with a variety of seamounts and submarine volcano
Submarine volcano
Submarine volcanoes are underwater fissures in the Earth's surface from which magma can erupt. They are estimated to account for 75% of annual magma output. The vast majority are located near areas of tectonic plate movement, known as ocean ridges...
es, representing the highest peaks of a complex chain of seamounts located in the Mid-Atlantic Ridge that are home to a diverse group of living creatures.
The isolated Dom João de Castro Bank
Dom João de Castro Bank
Dom João de Castro Bank is a large submarine volcano in the Azores in the central Atlantic Ocean. The volcano lies midway between the islands of Terceira and São Miguel and rises to within of the sea surface...
, located between São Miguel
São Miguel Island
São Miguel Island , nicknamed "The Green Island", is the largest and most populous island in the Portuguese Azores archipelago. The island covers and has around 140,000 inhabitants, 45,000 of these people located in the largest city in the archipelago: Ponta Delgada.-History:In 1427, São Miguel...
and Terceira
Terceira Island
Referred to as the “Ilha Lilás” , Terceira is an island in the Azores archipelago, in the middle of the North Atlantic Ocean. It is one of the larger islands of the archipelago, with a population of 56,000 inhabitants in an area of approximately 396.75 km²...
, is one such seamount included in this group. The hydrothermal vents located near it provide a good place to study the creatures that live in volcanic habitats.
The Azores also provide a good place to study deep-ocean hydrothermal vents. Deep-ocean hydrothermal vents, situated along the Mid-Atlantic Ridge, have been the target of various investigative projects by many types of scientists. Recently, some interesting communities of living creatures were discovered in the "Lucky Strike" and in the "Menez Gwen" hydrothermal fields, both located in the Azores Exclusive Economic Zone
Exclusive Economic Zone
Under the law of the sea, an exclusive economic zone is a seazone over which a state has special rights over the exploration and use of marine resources, including production of energy from water and wind. It stretches from the seaward edge of the state's territorial sea out to 200 nautical...
.
"Lucky Strike" is the largest known hydrothermal field, with 21 active vents spread over 150 km2 (57.9 mi2). The hydrothermal fluids reach temperatures of 330°C (626°F), very close to the boiling point corresponding to the force of pressure at 1,100 m (3,609 ft). The field's fauna is bio-geographically distinct from that of other hydrothermal fields, predominately rich in mussel
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s and associated species.
The "Menez Gwen" hydrothermal field is characterized by a 700 m (2,297 ft) volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
with a diameter of 17 km (10.6 mi). The hydrothermal fluids, with temperatures close to 280°C (536°F), emerge from various active vents at a depth of 850 m (2,789 ft). Large quantities of mussels cover the vents, and are accompanied by shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
s, crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, and many other species.