page_title: Azores
section_title: Physical geography
hierarchical_section_title: Azores / Geography / Physical geography
caption_attribution_description: English: The Sete Cidades twin lakes of São Miguel, Açores, Portugal.
context_page_description: The Azores, officially the Autonomous Region of the Azores, is one of the two autonomous regions of Portugal. It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atlantic Ocean, about 1,360 km west of continental Portugal, about 1,500 km west of Lisbon, in continental Portugal, about 1,500 km northwest of Morocco, and about 2,980 km southeast of Newfoundland, Canada.
  Its main industries are agriculture, dairy farming, livestock, fishing, and tourism, which is becoming the major service activity in the region. In addition, the government of the Azores employs a large percentage of the population directly or indirectly in the service and tertiary sectors. The capital is Angra do Heroísmo but the main city of the Azores is Ponta Delgada.
  There are nine major Azorean islands and an islet cluster, in three main groups. These are Flores and Corvo, to the west; Graciosa, Terceira, São Jorge, Pico, and Faial in the centre; and São Miguel, Santa Maria, and the Formigas Reef to the east. They extend for more than 600 km and lie in a northwest–southeast direction.
context_section_description: The archipelago of the Azores is located in the middle of the northern hemisphere of the Atlantic Ocean and extends along a west-northwest to east-southeast orientation (between 36.5°–40° North latitudes and 24.5°–31.5° West longitudes) in an area approximately 600 kilometres (373 miles) wide. The islands of the Azores emerged from what is called the Azores Plateau, a 5.8 million km² region that is morphologically accented by a depth of 2,000 metres (6,600 feet).
  From a geostructural perspective the Azores is located above an active triple junction between three of the world's large tectonic plates (the North American Plate, the Eurasian Plate and the African Plate), a condition that has translated into the existence of many faults and fractures in this region of the Atlantic. The westernmost islands of the archipelago (Corvo and Flores) are located in the North American Plate, while the remaining islands are located within the boundary that divides the Eurasian and African Plates.
  The principal tectonic structures that exist in the region of the Azores are the Mid-Atlantic Ridge, the Terceira Rift, the Azores Fracture Zone and the Glória Fault. The Mid-Atlantic Ridge is the main frontier between the American Plate and the African-Eurasian Plates that crosses the Azores Plateau between the islands of Flores and Faial from north to south then to the southwest; it is an extensive form crossed by many transform faults running perpendicular to its north–south orientation, that is seismically active and susceptible to volcanism.
  The Terceira Rift is a system of fractures that extends from the Mid-Atlantic Ridge to the Glória Fault that represents the main frontier between the Eurasian and African Plates. It is defined by a line of submarine volcanoes and island mounts that extend northwest to southeast for about 550 kilometres (342 miles), from the area west of Graciosa until the islets of the Formigas, that includes the islands of Graciosa, Terceira and São Miguel. Its northwest limit connects to the Mid-Atlantic Ridge, while the southeast section intersects the Gloria Fault southeast of the island of Santa Maria.
  The Azores Fracture Zone extends from the Glória Fault and encompasses a relatively inactive area to the south of the islands of the Central and Eastern groups north to the Terceira Rift, along a 45° angle. The Glória Fault, for its part, extends 800 kilometres (497 miles) along a linear line from the Azores to the Azores–Gibraltar Transform Fault.
  The island's volcanism is associated with the rifting along the Azores Triple Junction; the spread of the crust along the existing faults and fractures has produced many of the active volcanic and seismic events, while supported by buoyant upwelling in the deeper mantle, some associate with an Azores hotspot. Most of the volcanic activity has centered, primarily, along the Terceira Rift. From the beginning of the island's settlement, around the 15th century, there have been 28 registered volcanic eruptions (15 terrestrial and 13 submarine). The last significant volcanic eruption, the Capelinhos volcano (Vulcão dos Capelinhos), occurred off the coast of the island of Faial in 1957; the most recent volcanic activity occurred in the seamounts and submarine volcanoes off the coast of Serreta and in the Pico-São Jorge Channel. 
  The islands have many examples of volcano-built geomorphology including caves and lava tubes (such as the Gruta das Torres, Algar do Carvão, Gruta do Natal, Gruta das Cinco Ribeiras), the coastal lava fields (like the coast of Feteiras, Faial, the Mistério of Prainha or São João on Pico Island) in addition to the inactive cones in central São Miguel Island, the aforementioned Capelinhos on Faial, the volcanic complexes of Terceira or Plinian caldeira of Corvo Island.
  The islands of the archipelago were formed through volcanic and seismic activity during the Neogene Period; the first embryonic surfaces started to appear in the waters of Santa Maria during the Miocene epoch (from circa 8 million years ago). 
  The sequence of the island formation has been 
caption: The Lagoa das Sete Cidades, located within the Sete Cidades Massif, in Sete Cidades, São Miguel Island.
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