Fernando de Noronha
| Fernando de Noronha | |
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| Waters | Atlantic Ocean |
| Geographical location | 3 ° 51 ′ S , 32 ° 25 ′ W |
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| Number of islands | 13 (+8 cliffs) |
| Main island | Fernando de Noronha |
| Total land area | 26 km² |
| Residents | 3000 |
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Fernando de Noronha is a Brazilian archipelago of volcanic origin in the Atlantic , about 350 km east of mainland Brazil. Although it lies off the coast of Rio Grande do Norte , it belongs as a state district , officially Portuguese Distrito Estadual de Fernando de Noronha , to the state of Pernambuco and, with 14 other municipalities, since 2017 to the geographical-statistical Região Geográfica Imediata do Recife . The archipelago is named after the Portuguese trader Fernão de Loronha , to whom the archipelago was donated by the Portuguese crown for his merits in importing wood from Brazil.
geography
The archipelago consists of 21 separate land areas with a total area of 26 km². The main island, which bears the name of the archipelago, is both the largest island and the only one that is inhabited. Their area is 17 km². The Morro do Pico , the highest point on the island, measures 323 m.
In addition to the main island, there are the following small islands and cliffs :
Islands
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Cliffs
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Landscape image
Fernando de Noronha's vegetation consists mainly of plants that are typical of northern Brazil and that lose their leaves during the dry season. Trees can be found in high areas, but mainly shrubs on the plains. In the rainy season between March and August, the flora shows itself in all its splendor and abundance.
Waters
Fernando de Noronha has many natural pools. The most important coral occurrence is the Montastrea cavernosa . The islands are also known for their rich populations of dolphins and sea turtles . The Baía dos Golfinhos is home to the world's largest collection of dolphins. Over 1,000 spinner dolphins have already been counted there. Despite tourist use, there are strict nature conservation laws, such as the ban on touching the turtles and a ban on fishing. Because of the great biodiversity, the waters around the island are considered to be one of the best diving areas in Brazil.
Flora and fauna
The United Nations Environment Program counts 15 potentially endemic plant species, including two species of the genus Capparis , three species of Ceratosanthes , two species of Cayaponias , Moriordica , Cereus , Palicourea , Guettarda , Bumelia , Physalis and Ficus noronhae .
There are two endemic bird species on Fernando de Noronha, the Noronha olive tyrant ( Elaenia ridleyana ) and the Noronha vireo ( Vireo gracilirostris ). Both occur on the main island, the Noronha-Vireo also on the Ilha Rata. There is also an endemic breed of ear- spotted dove , Zenaida auriculata noronha . An endemic rodent of the Sigmodontinae , Noronhomys vespuccii , named after Amerigo Vespucci , has now become extinct. There are two species of endemic reptiles on the islands, a double sneak ( Amphisbaena ridleyi ) and a skink ( Trachylepis atlantica ).
climate
The climate is tropical hot all year round . The average temperature is 28 ° C. Two seasons can be clearly distinguished from one another: the dry season (September to February) and the rainy season (March to August). Short rain showers are repeatedly interrupted by the sunshine.
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Average monthly temperatures and rainfall for Fernando de Noronha
Source: wetterkontor.de
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geomorphology
The substructure of the Fernando de Noronha Archipelago is a conical underwater elevation that is around 60 kilometers wide at its base in a water depth of 4000 meters. In 100 meters water depth it decreases to a 3 to 4 kilometer wide abrasion platform on which the generally northeast-trending islands sit (the main island is oriented to the east-northeast). This underwater elevation belongs to a group of volcanic structures, all of which are located along the east-west striking Fernando de Noronha fault zone .
In the extension of the fracture zone to the west, the Ceará-Guyot rises on the continental slope . In the interior of the South American continent , 30 million years ago BP, phonolithic intrusives formed near Fortaleza , which are very similar to the phonolites on Fernando de Noronha. This suggests that the fracture zone has affected even the edge of the continental crust . About 150 kilometers to the west of Fernando de Noronha is on the same fault zone, the Rocas Atoll - a leveled from the Atlantic volcanic Guyot , who completely from Lithothamnium - algae reefs and biogenic sands covered.
geology
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The geological development of the Fernando de Noronha Archipelago can be broken down as follows (from young to old):
- Quaternary sediments
- Erosion phase
- Quixaba formation
- Erosion phase
- Remédios Formation and São José Formation (on the island of São José)
The Remédios formation , which forms the exposed substructure of the archipelago , begins with pyroclastic deposits that can reach more than 100 meters with great fluctuations in thickness. The formation consists of tuffs , breccias and volcanic agglomerates that exist in the central part of the main island. Fragments of alkali basalt , phonolite and phonolite porphyry , trachyte and essexite porphyry are found under the breccias . The fragments show the most varied orders of magnitude and can reach up to a meter. A fragment of alkali basalt trapped in the pyroclastics was dated by Cordani using the potassium-argon method and revealed a Middle Miocene ( Serravallian ) age of 12.3 million years BP . This result represents a maximum age for the pyroclastics.
The pyroclastics were then intruded in the Upper Miocene ( Tortonian ) around 9 million years ago BP from phonolithic and trachytic dammings and tunnels of various compositions. A total of 11 phonolite domes can be made out on the main island, each with a diameter of up to 1 kilometer. The gears consist predominantly of Natrongesteinen ( lamprophyres as Monchiquit , Fourchit and Camptonit as well as other rare such as Ankaratrit , Augitit , Alkalitrachyt , limburgite , Sannait , Olivinteschenit , Essexitporphyr, Olivinnephelinit , basanite and Gauteit ). Preferred directions of strike of the corridors are northeast (N 045) and southeast (N 135). Effusive equivalents of the gangue passed but were removed by the subsequent erosion phase .
The Quixaba formation that follows above is built up from a series of ankaratrite rivers that alternate with pyroclastics of the same chemistry. On the main island, the Quixaba formation forms two plateau levels , with the eastern one reaching up to 180 meters above sea level . The formation is also present on some of the smaller islands, particularly on Ilha Rata. In general, the lava flows are flat, but depending on the local flow direction, they can dip up to 30 ° to the south. The lavas are massive inside, but become vesicular on the lying and hanging walls and form vacuoles and amygdals . Individual rivers are usually only a few meters thick, but in exceptional cases, such as on the cliff in Praia Sancho, they can be up to 40 meters thick. Very thin rivers, often only a few centimeters long, of Melilith- bearing Ankaratriten switch themselves on from time to time. These Melilithankaratrite alternate with lapillite tuff , which encloses bombs of the same material up to a decimeter in size . The pyroclastic layers in the Quixaba Formation consist of tuffs, tuff breccias and agglomerates, with the clasts originating from the associated lava flows. The breccias can contain blocks up to 2 meters in size. Perfectly shaped bombs and pieces of knitted lava are relatively common. The grain size distribution of the pyroclastites can be quite irregular. They usually show quite coarse stratification , but can also be finely stratified in places. The 130 meter wide Tamandaré chimney at the northeast end of the main island, which penetrates the lower lava flow unit, is impressive . The chimney walls consist of ankaratite with remains of the chimney filling made of tuff, scoria and agglomerate. The walls are also criss-crossed by corridors. The fact that hot solutions emerged from the chimney is shown by the perfect calcite scalenohedra in fractures in the breccias and agglomerates.
Some coarse-grained nephelinite dikes on the main island are also assigned to the Quixaba Formation.
The age of the Quixaba formation is given as 3.3 to 1.7 million years BP and thus falls into the Upper Pliocene and Lower Pleistocene ( Piacenzian and Gelasian ).
The position of the basanite of the São Jose formation on the island of the same name is not clear. It was dated 9.5 million years BP (Tortonium) and thus seems to be clearly older than the Quixaba Formation. It may be an equivalent of the Remédios formation. A special feature of the formation are very beautiful dunite inclusions .
Note: Not all scientific authors recognize this K-Ar age and point to irregularities in the dating. For Schwab and Block as well as Ulbrich, the Basanites are more likely to be assigned to the Quixaba formation.
After the end of the volcanic activity that produced the Quixaba formation, erosion took place again in the Pleistocene. Extensive abrasion platforms developed, especially on the main island. The sea level fluctuations during the Pleistocene left sand and debris deposits from the beach area, calcareous algae reefs and marine sands on these platforms. The platform levels are at 9, 12 and 30 meters above sea level, with the extended 30-meter level in the interior of the island being undoubtedly the most significant. During the Lower Pleistocene sea level, which was 6 meters below today's level, extensive sandy beaches formed in the south and south-east of the archipelago. The southeast trade winds blew the sand up to 20 meters high dunes, which created a cordon between the Ilha Rata and the Santo Antônio peninsula in the northeast of the main island. Not quite as long dunes emerged on the main island at the entrance to Praia Sueste.
After the sea level rose again in the Holocene , the dunes were partially flooded and unaffected areas hardened into Caracas calcarenite . This light, cream-colored sediment is largely composed of lime particles from Corallinaceae algae. Only a small proportion of the particles (over the underlying, melanocratic Ankaratriten up to 25%) come from the volcanic rocks. The solidification of the inclined calcarenite depends on the progress of the calcium cementation. Upper layers of the calcarenite contain calcium phosphates derived from bird guano .
The Fernando de Noronhas volcanic rocks, like the volcanic rocks on Tristan da Cunha , Gough , the Canaries , Sankt Helena and Trindade, represent a characteristic undersaturated differentiation trend of alkaline magmas. The SiO 2 content of the sodium-reinforced rocks varies between 34.4% (Melilithankaratrite) and 60.8% (Alkalitarchyte). Fernando de Noronha is one of the world's most alkaline volcanic provinces among the oceanic islands of volcanic origin . Strangely enough, the lighter, SiO 2 -rich magma differentiates were extracted at the beginning (Remédios formation). Only after a hiatus of 5 to 6 million years did the ultramafic volcanism of the Quixaba formation set in.
population
The main island has been inhabited for about 400 years and had an estimated 3021 inhabitants as of July 1, 2018. The majority of them live in the main town of Vila dos Remédios.
According to the state constitution of Pernambuco of 1989, Fernando de Noronha is constituted as a state district and is therefore the only area in Brazil that does not belong to any municipality. Statistically, however, the district is equated with a municipality and a conversion into a municipality is planned for the future. Fernando de Noronha is smaller than all of Pernambuco's municipalities and at the same time has a higher standard of living than them.
Economy and Transport
Twenty years ago the population lived almost exclusively from fishing and agriculture. Today this area employs less than 100 people. A large part of the island's population is active in the tourism sector. The island is advertised as one of the world's best diving spots.
There are daily flights from Fernando de Noronha airport on the main island (airport IATA code: FEN) to Recife (REC) and Natal (NAT).
history
Amérigo Vespucci first mentioned the archipelago in 1503 . As a result, the French and Dutch came to the islands, but in the end the Portuguese came to rule. Both Portugal and Brazil long used the island as a penal colony . During the Second World War , the island was declared a federal territory and American soldiers came to the island for a short time. Subsequently, the islands were under the Brazilian military until 1987. The archipelago has belonged to Pernambuco since 1988. Since then, the establishment of " soft tourism " has started. Most of the smaller islands and an area of around 8 km² on the main island have been protected as the Fernando de Noronha Marine National Park since 1988 .
Including the protected sea area, the park covers 112.7 km². In 2001, he was together with the Rocas Atoll by the UNESCO for World Heritage declared.
Web links
- Entry on the UNESCO World Heritage Center website ( English and French ).
- Official site ( Portuguese / English )
- Information from a German emigrant about Fernando de Noronha
- Location of the national park ( Memento from December 13, 2007 in the Internet Archive )
Individual evidence
- ^ Helmuth Taubald: Brazil. (= Travel DuMont correctly ). DuMont Reiseverlag, Ostfildern 2009, ISBN 978-3-7701-7632-8 , p. 80.
- ↑ Fernando de Noronha , Islands of Brazil, UN System-wide Earthwatch
- ^ MD Carleton, SL Olson: Amerigo Vespucci and the rat of Fernando de Noronha: a new genus and species of Rodentia (Muridae, Sigmodontinae) from a volcanic island off Brazil's continental shelf (= American Museum Novitates . Volume 3256 ). 1999, OCLC 41061343 ( handle.net ).
- ^ P. Mausfeld, A. Schmitz, W. Böhme, B. Misof, D. Vrcibradic, CF Duarte: Phylogenetic affinities of Mabuya atlantica Schmidt, 1945, endemic to the Atlantic Ocean archipelago of Fernando de Noronha (Brazil): Necessity of partitioning the genus Mabuya Fitzinger, 1826 (Scincidae: Lygosominae) . In: Zoologischer Anzeiger . tape 241 , 2002, pp. 281-293 .
- ↑ Fernando FM Almeida: Arquipélago de Fernando de Noronha. Registro de monte vulcânico do Atlântico Sul . In: C. Schobbenhaus, DA Campos, ET Queiroz, M. Winge, M. Berbert-Born (eds.): Sítios Geológicos e Paleontológicos do Brasil . 2000, p. 361-368 ( gov.br ).
- ↑ a b U. G. Cordani: Idade do vulcanismo no Oceano Atlântico Sul . In: Instituto de Geociências e Astronomia, Boletim IGA . tape 1 , 1970, p. 9-75 .
- ↑ FFM de Almeida: Geologia e petrologia do arquipélago de Fernando de Noronha (= Monografia . Volume 13 ). DNPM / DGM, Rio de Janeiro 1955, OCLC 68145443 .
- ↑ a b M. NC Ulbrich: Petrography of alkaline volcanic-subvolcanic rocks from the Brazilian Fernando de Noronha Archipelago, Southern Atlantic Ocean . In: Geoch. Bras. tape 8 , no. 1 , 1994, p. 21-29 .
- ↑ V. Maringolo: Estudo petrográfico e químico de alguns Diques ultramáficos e máficos do Arquipélago de Fernando de Noronha, PE . Dissertation. Instituto de Geociências, Universidade de São Paulo, São Paulo 1994, p. 145 .
- ^ MN C. Ulbrich, E. Ruberti: Nova ocorrência de rocha basanítica no Arquipélago de Fernando de Noronha . In: Congresso Brasileiro de Geologia, 37, SBG. Anais, 2 . São Paulo 1992, p. 83-84 .
- ^ RG Schwab, W. Block: Geochemical distribution pattern of magmatites from the Archipelago of Fernando de Noronha . In: Zentralblatt für Geologie und Palaeontologie . tape 1 , no. 9-10 , 1985, pp. 1477-1483 .
- ↑ JC Branner: The eolian sandstone of Fernando de Noronha . In: American Journal of Sciences . tape 39 , 1890, p. 247-257 .
- ↑ Fernando de Noronha - Panorama. In: cidades.ibge.gov.br. IBGE , accessed July 25, 2019 (Brazilian Portuguese).
Heritage: Historic City of Ouro Preto (1980) | Historic Center of Olinda (1982) | Jesuit Missions of the Guaraní (1983) | Historic Center of Salvador da Bahia (1985) | Shrine of Bom Jesus de Matosinhos (1985) | Brasília (1987) | Serra da Capivara National Park (1991) | Historic Center of São Luís (1997) | Historic Center of the City of Diamantina (1999) | Historic center of the city of Goiás Velho (2001) | São Francisco Square in São Cristóvão (2010) | Rio de Janeiro : Carioca landscapes between mountains and sea (2012) | Ensemble of Modernism in Pampulha (2016) | Valongo-Kai Archaeological Site (2017)
Natural heritage: Iguaçu National Park (with the Iguazú waterfalls ) (1986) | Atlantic Forest Protected Areas on the Coast of Discovery (1999) | Southeast Atlantic Forest Reserves (1999) | Central Amazon protected area (2000) with Jaú National Park (2003) | Pantanal Protected Area (2000) | Brazilian Atlantic Islands: Fernando de Noronha and Rocas Atoll Reserves (2001) | Cerrado Protected Areas: Chapada dos Veadeiros and Emas National Parks (2001)
Cultural / Natural Heritage: Paraty and Ilha Grande - Culture and Biodiversity (2019)