Thehydrothermal vents and seamounts of the Azores (Portuguese:fontes hidrotermais e montes submarinos dos Açores) are a series ofAtlanticseamounts andhydrothermal vents that are part of theMid-Atlantic Ridge system, giving rise to the archipelago and bathymetric region of theAzores. These geological structures, formed from masses ofbasalt (typical of mid-ocean regions), are of a geomorphological interest due to their rich deposits ofore. In addition it fosters a rich ecosystem of diverse subaquatic plant and animal life. There arefood chains within this environment, for example, that are purelychemosynthetic, and do not need sunlight forphotosynthesis.
The Azores consists of an extensive marine and terrestrial system of hundreds of active submarine mounts and volcanoes that extend from the Mid-Atlantic Ridge. The islands of the Azores are the visible representation of the complex ridge of undersea mountains that extend from Iceland to Antarctic.[1] Below the waters of the Azores are undersea valleys and large mountains that are many times larger than the terrestrial continental mountain ranges.[1] Formed bydivergent boundary plate tectonics, the region is fractured and susceptible toearthquakes and natural volcanism, resulting in effusive or explosive volcanism. Beneath the Atlantic the formative processes continue to occur producing new land area such as the volcanic eruptions atCapelinhos orSerreta, but also through the venting of gases and pillow lavas, supporting a rich ecosystem.
Hydrothermal vent is the name given to a type offumarole found in the ocean, with elevated temperatures, rich in dissolved minerals, resulting from the infiltration of ocean water into the Earth's crust and magma chambers.[1] When expelled and contacting the cold waters, it results in a precipitation of mineral deposits, forming a characteristic plume of muddy waters and expelled minerals.[1]
Seven large hydrothermal fields have been discovered within the waters of the Azores:
These sites, with the exception of the Moytirra system, are located in the southern part of the archipelago, and have been investigated by national and international scientists. The isolatedDom João de Castro Bank is also considered in this group; located betweenSão Miguel andTerceira, the seamount is one of the highest independent seamounts in the archipelago and home to a thriving marine volcanic habitat.
In 2010, a shallow hydrothermal field was discovered off the Ponta da Espalamaca, on the island ofFaial, showing evidence of de-gasification.
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. TheWorld Wildlife Fund 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 also provide a good place to study deep-ocean hydrothermal vents; various investigative projects by many scientists have documented the relationship between divergent boundary zones and subaquatic ecosystems. Communities of living creatures were discovered in theLucky Strike Hydrothermal Field and theMenez Gwen Hydrothermal Field, both located within the Azores'Exclusive Economic Zone. TheLucky Strike field has a bio-geographically fauna, distinct from that of other hydrothermal fields in the archipelago, characterized bymussels and associated species. Meanwhile, theMenez Gwen field is a breeding ground for mussels,shrimp and crab species.
These hydrothermal environments are characterized by an elevated number of endemic and exclusive species; such as shrimp (likeRimicaris exoculata) or fish (such asPachycara saldanhai), among others that exist in these areas.[1] In addition, thechemotrophic subaquatic environment (as opposed tophototropiclithosphere) has resulted in a trophic habitat that is original and delicate. In these environments bacteria replace plants, through chemosynthesis, by transforming carbon molecules and nutrients into organic matter.[1] Many of these ecosystems were only discovered in the Atlantic between 1977 and 1992.[1]
| Grupo Oriental (Eastern Group) |  | |
|---|---|---|
| Grupo Central (Central Group) | ||
| Grupo Ocidental (Western Group) | ||
| Islets | ||
| Caves and geological features | ||
| Reefs, banks andseamounts | ||
