Baixa da Ponta dos Rosais

Baixa da Ponta dos Rosais
Oceanic plateau (Baixa)
A view at the edge of Ponta dos Rosias, the Baixa is located some 3 miles (4.8 km) north of this point
Official name: Baixa dos Rosais
Named for: Ponta dos Rosais
Country  Portugal
Autonomous region  Azores
Islands Eastern Group
Location Azores Platform, Mid-Atlantic Ridge, Atlantic Ocean
Highest point Baixa
 - coordinates 38°46.80′N 28°23.70′W / 38.78000°N 28.39500°W / 38.78000; -28.39500
Depth 20 m (66 ft)
Biome Marine (ocean)
Geology Alkali basalt, Tephra, Trachyte, Trachybasalt
Orogeny Volcanism
Period Holocene

The Baixa da Ponta dos Rosais is an oceanic plateau north-northwest of the coast of Ponta dos Rosais, municipality of Velas, island of São Jorge, in the Portuguese archipelago of the Azores. The seamount region is located 3 miles (4.8 km) from the coast, and 9 miles (14 km) from the central port of Velas, from where it is a popular destination for divers who frequent the Azores.[1]

Geography

Pertaining to the northern civil parish of Rosais, Ponta dos Rosais is an extension of the north-northwest and south-southeast fissural formation of the island, along a fault system that extends from São Miguel to São Jorge, called the Terceira Rift. Effusive and explosive submarine eruptions across these fissural faults gave rise to the long, slender island of São Jorge. Oceanic plateaus extending into the ocean, north and south of the island, are offshoots of these formative forces.

The Baixa is one of these plateaus, made of submerged oceanic basalt cliffs created by fissural tectonics, with accentuated slopes aligned northwest to southeast from Ponta dos Rosais.[1] Its location, with a mix of open sea and currents, means that the area's condition varies and is frequently turbulent.[1]

Biome

Sandy deposits from pyroclastic surges at the point of Rosais has meant that a small area of the Baixa is favourable for the congregation of sea mammals and marine species.[1]

Within a radius of 20 metres (66 ft) there are elevated number of animal species, in addition to sea plants. Predominantly, the area is a habitat for brown alga (Stypopodium zonale), red alga (Asparagopsis armata), Sawfish, Vadigo (Campogramma glaycos), Frigate tuna (Auxis thazard) and anchovy, in addition to Needlefish, Grouper and Hake, among others; there are more than 69 different species (the area has a 7.2 Margalef scale/biodiversity index-rating), and it has been defended as a candidate for protection, owing to the biodiversity in the region.[1][2]

References

Notes
  1. 1 2 3 4 5 "Baixa da Ponta dos Rosais" (in Portuguese). Horta (Azores), Portugal: Department of Oceangraphy and Fisheries/University of the Azores. 2012.
  2. ↑ Santo et al. (1995)

Sources

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