João Valente (reef)

Last updated
João Valente
Cape Verde location map Topographic.png
Red triangle with thick white border.svg
João Valente
between the islands of Boa Vista and Maio
Highest point
Elevation −1 m (−3.3 ft)
Listing Seamounts
Coordinates 15°44′27″N23°5′26″W / 15.74083°N 23.09056°W / 15.74083; -23.09056 Coordinates: 15°44′27″N23°5′26″W / 15.74083°N 23.09056°W / 15.74083; -23.09056  
Geography
Location between the islands of Boa Vista and Maio
Geology
Mountain type Stratovolcano

João Valente is a reef located nearly between the islands of Boa Vista (20 nmi, 35 km) and Maio (25 mmi, 45 km). The reef's lowest point is about 100 meters above sea level. The seamount is about 1,000 meters tall. [1] The highest point is at sea level and dominates the area of about 1,000 to 2,000 km2, probably and erosion affected the volcano (Guyot). [2] The reef is partly visible during low tide. It is not the only shallow part, another shallow part is SSW of the reef located WNW of Maio and northeast of Santiago at Calheta de São Miguel.

Boa Vista, Cape Verde Cape Verde island

Boa Vista, also written as Boavista, is a desert-like island that belongs to the Cape Verde Islands. At 631.1 km2 (243.7 sq mi), it is the third largest island of the Cape Verde archipelago.

Maio, Cape Verde easternmost of the Sotavento islands; municipality (concelho) of Cape Verde

Maio is the easternmost of the Sotavento islands of Cape Verde. Maio is located south of the island of Boa Vista and east of Santiago. Administratively, the island forms one concelho (municipality): Maio.

Calheta de São Miguel Settlement in Santiago, Cape Verde

Calheta de São Miguel is a city in the northern part of the island of Santiago, Cape Verde. In 2010 its population was 3,175. It is situated on the east coast, 31 km north of the capital Praia. It is the seat of São Miguel municipality.

During the Ice Age, it was a larger island that once included Boa Vista and that island separated Maio by about 2 to 5 km, it was in the middle part and had two isthmus connecting the former Boa Vista and the Southern peninsulas. Around 7,000 to 6,000 BC, the isthmus were flooded and separated the islet from Boa Vista. João Valente was a flat island until around 2,000 to 1,000 BC when a rise in sea level flooded the whole island and became a reef.The reef was mentioned as "Baixa" (Portuguese for lower as being underwater and a submerged rocky area) in a 1598 map titled Insulae Capitis Viridis which is now at the National Library of France. [3] In a map from 1747 by Jacques-Nicolas Bellin, the reef was mentioned as a submerged rock named Jean Letton (Roche de Jean Letton, Middle Dutch: Rotz van Jean Letton, Portuguese: Rochas de João Leitão). On April 20, 1806, the English ship The Lady Burgess sank into the reef. [4]

Jacques-Nicolas Bellin French hydrographer, geographer and member of the philosophes

Jacques Nicolas Bellin was a French hydrographer, geographer, and member of the French intellectual group called the philosophes.

The high biodiversity of fishes in the reef along with other seamounts discovered in 1981, ichthyofauna has been studied. [1] [5] Also it is the area where other sealife including coral and mollusks (i.e. sea snails, cone snails, sea slugs, nudibranchs) are founded and may be Cape Verde's most abundant including the waters surrounding Boa Vista. Expeditions were made in the area and surrounding the reef including the 1990s, 2002 by Atlântico Selvagem, 2004 and recently in the 2000s

Related Research Articles

Geography of Nauru

Nauru is a tiny phosphate rock island nation located in the South Pacific Ocean south of the Marshall Islands in Oceania. It is only 53 kilometres (33 mi) south of the Equator at coordinates 0°32′S166°55′E. Nauru is one of the three great phosphate rock islands in the Pacific Ocean—the others are Banaba in Kiribati and Makatea in French Polynesia.

History of Cape Verde aspect of history

The recorded history of Cape Verde begins with Portuguese discovery in 1456. Possible early references go back around 2000 years.

Pratas Islands island group in the north of the South China Sea

The Pratas Islands, also known as the Dongsha Islands and Tungsha Islands, are three atolls in the north of the South China Sea. They consist of one island, two coral reefs and two banks, and are located about 170 nautical miles southeast of Hong Kong. The Republic of China (Taiwan) controls them and has declared part of them the Dongsha Atoll National Park. The People's Republic of China claims them as part of China.

Gardner Pinnacles Two barren rock outcrops surrounded by a reef in the Northwestern Hawaiian Islands

The Gardner Pinnacles are two barren rock outcrops surrounded by a reef and located in the Northwestern Hawaiian Islands at 24°59′56″N167°59′58″W.

Maro Reef A largely submerged coral atoll in the Northwestern Hawaiian Islands

Maro Reef is a largely submerged coral atoll located in the Northwestern Hawaiian Islands. It was discovered in 1820 by Captain Joseph Allen of the ship Maro, after whose ship the reef was named. With a total area of 747 square miles (1,935 km2), it is the largest coral reef in the Northwestern Hawaiian Islands. It contains 37 species of stony coral. Unlike most atolls, the coral extends out from the center like spokes on a wheel. Located about 850 miles northwest of Honolulu, Hawaii, Maro Reef contains about 1 acre (4,000 m2) of dry land which itself can be submerged depending on the tides. Some scientists believe that it "may be on the verge of drowning" because the reefs are detached and are vulnerable to strong storm waves.

The Dollabarat Reef is a shoal situated 5 km south-southeast of the Formigas Islets, on the Formigas Bank in the Azores archipelago.

Pacific Remote Islands Marine National Monument

The Pacific Remote Islands Marine National Monument is a group of unorganized, mostly unincorporated United States Pacific Island territories managed by the Fish and Wildlife Service of the United States Department of the Interior and the National Oceanic and Atmospheric Administration of the United States Department of Commerce. These remote refuges are "the most widespread collection of marine- and terrestrial-life protected areas on the planet under a single country's jurisdiction". They protect many endemic species including corals, fish, shellfish, marine mammals, seabirds, water birds, land birds, insects, and vegetation not found elsewhere.

Stellwagen Bank National Marine Sanctuary marine protected area off of Massachusetts, USA

Stellwagen Bank National Marine Sanctuary is an 842-square-mile (638-square-nautical-mile) federally protected marine sanctuary located at the mouth of Massachusetts Bay, between Cape Cod and Cape Ann. It is known as an excellent whale watching site, and is home to many other species of marine life.

Ilhéu de Sal Rei island

Ilhéu de Sal Rei is an uninhabited islet near the coast of Boa Vista Island, Cape Verde. It is located 1 km southwest of the island capital Sal Rei. Its area is 89 ha (0.34 sq mi) and its highest point is 27 m (88.6 ft).

Ocean bank A part of the sea which is shallow compared to its surrounding area

An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the seabed which is shallow compared to its surrounding area, such as a shoal or the top of an underwater hill. Somewhat like continental slopes, ocean banks slopes can upwell as tidal and other flows intercept them, resulting sometimes in nutrient rich currents. Because of this, some large banks, such as Dogger Bank and the Grand Banks of Newfoundland, are among the richest fishing grounds in the world.

Morro Negro mountain in Cap-Vert

Morro Negro is a hill located near the east coast of the island of Boa Vista, Cape Verde. Its elevation is 156 m. The nearest village is Cabeça dos Tarrafes, 5.5 km to the northwest.

São Jorge (Santiago) Settlement in Santiago, Cape Verde

São Jorge is a settlement in the central part of the island of Santiago, Cape Verde. It is part of the São Lourenço dos Órgãos municipality. In 2010 its population was 6. It is situated 2.5 km southwest of João Teves and 4 km southeast of Picos. Its elevation is 319 meters.

The Princess Alice Bank is a submerged seamount that is located 50 nmi (93 km) to the southwest of the island of Pico and 45 nmi (83 km) to the southwest of the island of Faial in the Portuguese archipelago of the Azores. The western area of the bank has a minimum depth of 35 metres (115 ft), with clear waters that allow the observation of the ocean floor from the surface. With an abundance of biodiversity, the Bank is a fishing area, in addition to being an important diving spot of the Atlantic Ocean.

Nintoku Seamount A flat topped seamount in the Hawaiian-Emperor seamount chain

Nintoku Seamount or Nintoku Guyot is a seamount and guyot in the Hawaiian-Emperor seamount chain. It is a large, irregularly shaped volcano that last erupted 66 million years ago. Three lava flows have been sampled at Nintoku Seamount; the flows are almost all alkalic (subaerial) lava. It is 56.2 million years old.

Tizard Bank

The Tizard Bank, 10°15′N114°30′E, in Chinese known as 郑和群礁 and Zhenghe Qunjiao, is a partially sunken atoll and one of the significant maritime features of the north-western part of the Spratly Islands. It is claimed by the China, Taiwan and Vietnam, and various parts of it are occupied by these nations.

Farol de Fontes Pereira de Melo lighthouse in Cape Verde

Farol de Fontes Pereira de Melo is a lighthouse at the northeastern point of the island of Santo Antão in northwestern Cape Verde. It is situated on the headland Ponta de Tumbo, 2 km east of Janela, 6 km southeast of Pombas and 15 km northeast of Porto Novo. The lighthouse was named after Fontes Pereira de Melo, prime minister of Portugal for several times between 1871 and 1886. It is a white octagonal masonry tower, 16 meters high. Its focal height is 162 meters above sea level, and its range is 17 nautical miles. The adjacent building for the lighthouse keeper is abandoned and in poor condition.

Cadamosto Seamount A seamount in the North Atlantic Ocean southwest off the island of Brava, Cape Verde

The Cadamosto Seamount is a seamount in the North Atlantic Ocean just 20 km southwest of the island of Brava, Cape Verde.

Cape Verde Rise

The Cape Verde Rise is an oceanic feature that includes the Cape Verde Islands and the areas north and east of the islands and west of the African Continental Shelf as well as Mauritania and Senegal.

Farol da Preguiça lighthouse in Cape Verde

Farol da Preguiça is a lighthouse located near the shore of Baía de São Jorge in Preguiça on the island of São Nicolau in northern Cape Verde. It is a masonry hut, coloured white. It sits at about 18 meters above sea level in the village, it is seven meters tall and its focal height is at 25 meters above sea level. Its focal range is 5 nautical miles. Its characteristic is Fl (2+1) R 15s.

Ponta do Lobo Lighthouse lighthouse in Cape Verde

Ponta do Lobo Lighthouse is a lighthouse located near the headland named Ponta do Lobo, in the southeastern part of the island of Santiago, Cape Verde. The lighthouse is located about 4 km east of the nearest village, Vale da Custa, and 11 km northeast of the capital Praia. The lighthouse was built in 1887 and is the island's second oldest. It is a 9 metres high trapezoidal tower, attached to a single storey keeper's house. Its class of light is Fl (4) W 15s., its focal height is at 17 meters above sea level and its range is 10 nautical miles.

References

  1. 1 2 Monteiro, Pedro; Ribeiro, Daniel; Silva, José A.; Bispo, João; Gonçalves, Jorge M. S. (2008). Ichthyofauna Assemblages from Two Unexplored Atlantic Seamounts. Northwest Bank and João Valente Bank (Cape Verde Archipelago). 72. Scientia Marina. p. 138. ISSN   0214-8358.
  2. ↑ Ramalho, Richard A.S. (2011). Building the Cape Verde Islands. Berlin: Springer. p. 14. doi:10.1007/978-3-642-19103-9. ISBN   978-3-642-19102-2.
  3. ↑ "Insulae Capitis Viridis" (in Latin). 1598.
  4. ↑ "The Lady Burgess, 1806 (VAL-002). Wreckage History". Arqueonautas Worldwide.
  5. ↑ Gonçalves, Jorge M. S. Underwater Surveys of Ichthyofauna from João Valente Coastal Seamount and Boavista Island (Cape Verde) (PDF). AtlamticoSelvagem.org., a poster presentation


This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.