Fernando de Noronha

Fernando de Noronha is a Brazilian archipelago of volcanic origin in the Atlantic Ocean, about 350 kilometers east of the Brazilian mainland, and is part of the State of Pernambuco. Is named the archipelago after the Portuguese merchant Fernão de Loronha, which the archipelago was given by the Portuguese crown for services rendered to the wood imported from Brazil.

• 2.1 waters

Geography

The archipelago consists of 21 separate areas of land with a total area of 26 km ². The main island, which bears the name of the archipelago, is also the largest island and the only one that is inhabited. Its area is 17 km ². The Morro do Pico, the highest point on the island, measuring 321 m.

In addition to the main island to find the following small islands and cliffs:

Islands

• Ilha Rata
• Ilha da Conceição ( do Morro de Fora )
• Ilha de São José
• Ilha do Chapéu do Nordeste

• Ilha Trinta Réis
• Ilha Rasa
• Ilha do Chapéu Sueste
• Ilho dos Ovos

• Ilha do Meio
• Ilha do Lucena
• Ilha do Cuscuz
• Ilha Cabeluda

Cliffs

• Rochedo do Morro do Leão
• Rochedo do Morro da Viuvinha
• Cliff at Ilha dos Ovos

• Rochedo da Ilha do Frade
• Rochedo das Pedras Secas
• Cliff near Ponta das Caracas and Baía Sueste

• Rochedo Sela Gineta
• Rochedo Homeboys

Landscape

The vegetation of Fernando de Noronha consists mainly of plants that are typical of northern Brazil and lose their leaves during the dry season. In high altitude areas, however, trees are found on the plains mostly shrubs. In the rainy season from March to August, the plant world shows in all their glory and wealth.

Waters

Fernando de Noronha has many natural water basin. The most important coral deposits is the Montastrea cavernosa. The islands are also known for their rich stocks of dolphins and sea turtles. In the Baia dos Golfinhos is the world's largest collection of dolphins. There, more than 1,000 spinner dolphins were counted. Despite numbers of tourists, there are strict laws on nature protection, such as a prohibition to touch the turtles, and a fishing ban. Because of the great diversity of species, the waters are around the island as one of the best diving areas of Brazil.

Flora and Fauna

The United Nations Environment Programme has 15 potentially endemic plant species, including two species of the genus Capparis, three types of Cerato Anthes, two types of Cayaponias, Moriordica, Cereus, Palicourea, Guettarda, Bumelia, physalis and Ficus noronhae.

There are at Fernando de Noronha two endemic bird species, the Noronha Olivtyrann ( Elaenia ridleyana ) and Noronha - Vireo ( Vireo gracilirostris ). Both are found on the main island of Noronha Vireo also on Ilha Rata. There is also an endemic race of Latticed Dove, Zenaida auriculata noronha. An endemic rodent Sigmodontinae, which is now extinct after Amerigo Vespucci named Noronhomys vespuccii. On the islands there are two types of endemic reptiles, a double -worm ( amphisbaena ridleyi ) and a skink ( Trachylepis atlantica).

Climate

The climate is tropical, hot all year round. The average temperature is 28 ° C. Two seasons are easy to distinguish: the dry season (September to February) and the rainy season (March to August). Brief rain showers are here again and again interrupted by the sunshine.

Geomorphology

The base of the Fernando de Noronha Archipelago is a conically tapered sub- sea survey, which is about 60 kilometers wide at its base at 4000 meters water depth. In 100 meters water depth, it decreases to a 3-4 km wide Abrasionsplattform who sit the generally north- trending islands ( the main island is oriented to the east-northeast ). This sub- sea survey belongs to a group of Vulkanbauten, all entlangt are arranged east-west - trending Fernando de Noronha Fracture Zone.

In the extension of the fracture zone to the west rises at the continental slope of the Ceará - Guyot. Next in the interior of the South American continent phonolithische intrusives have formed 30 million years ago in Fortaleza BP, which are similar to the phonolites on Fernando de Noronha much. This suggests that the fracture zone has even affected the edge of the continental crust. About 150 kilometers to the west of Fernando de Noronha is on the same fracture zone das Rocas Atoll - a leveled from the Atlantic volcanic Guyot, which is completely bedeck of Lithothamnium algae reefs and biogenic sands.

Geology

The geological development of the Fernando de Noronha archipelago can be divided as follows ( from young to old):

• Quaternary sediments
• Erosion phase
• Quixaba lineup
• Erosion phase
• Remédios lineup and São José Formation ( on the island of São José )

The substructure of the open-minded group of islands forming Remédios lineup begins with pyroclastic deposits that can reach more than 100 feet below large thickness changes. The formation consists of tuffs, breccias and volcanic agglomerates, which are pending in the central part of the main island. Among the breccias are found fragments of alkali basalt, phonolite and Phonolithporphyr, trachyte and Essexitporphyr. The fragments show a wide variety of sizes and can reach up to over a meter. A trapped in the alkali basalt pyroclastics fragment was dated from Cordani with the potassium - argon method and gave a mittelmiozänes ( Serravallium ) age of 12.3 million years BP. This result represents a maximum age for the tephra

The pyroclastics were then intruded by a wide variety of phonolite and trachytic lava domes and corridors composition in the Upper Miocene ( Tortonian ) to around 9 million years BP. On the main island a total of 11 Phonolithdome can be identified that reach up to 1 kilometer in diameter. The courses consist mainly of Natrongesteinen ( lamprophyres as Monchiquit, Fourchit and Camptonit and other rarities such as Ankaratrit, Augitit, Alkalitrachyt, Limburgit, Sannait, Olivinteschenit, Essexitporphyr, Olivinnephelinit, basanite and Gauteit ). Preferred strike directions of the transitions are North (N 045) and Southeast (N 135). Effusive equivalents of the dyke rocks existed, but were removed by subsequent erosion phase.

The following Quixaba about lineup is made ​​up of a series of Ankaratritflüssen that interact with store pyroclastics of the same chemistry. On the main island of the Quixaba lineup forms two plateau levels, with the eastern reaches up to 180 meters above sea level. The formation is also present on some of the smaller islands, especially on Ilha Rata. In general, the lava flows lie flat, but may occur according to the local flow direction up to 30 ° to the south. The lavas are solid in their interior, but are bubbled to the footwall and hanging wall, forming vacuoles and Amygdalen from. Individual flows are usually only a few meters thick, but up to 40 meters in exceptional cases, such as the cliff in Praia Sancho are powerful. Very thin, often only a few centimeters measured fluxes of melilite leading Ankaratriten switch on occasionally. This Melilithankaratrite exchange store with Lapillituff, including large bombs of the same material plenty to decimeters. The pyroclastic layers in the Quixaba lineup consist of tuffs and agglomerates Tuffbrekzien, the clasts from the associated lava flows originate. The breccias may contain blocks up to 2 meter size. Perfectly shaped bombs and Stricklavabruchstücke are relatively common. The grain size distribution of the Pyroklastite can be quite irregular. They usually show quite rough stratification, can at times also be finely layered. Impressive is the 130 -meter-wide Tamandaré vent on the northeast end of the main island, crashed through the lower Lavaflusseinheit. The chimney walls are made of Ankaratrit with remnants of the chimney filling tuff, scoria and agglomerate. The walls are also crossed by corridors. That hot solutions leaked on vent, shows up at the perfect Kalzitskalenoedern in fractions of the breccias and agglomerates.

Some coarse-grained Nephelinitgänge on the main island of Quixaba formation are also assigned.

The age of the Quixaba formation is given as 3.3 to 1.7 million years BP and therefore falls into the Upper Pliocene and Lower Pleistocene ( Piacenzium and Gelasian ).

The position of the Basanits the São Jose - formation on the island of the same name is not unique. He was at 9.5 million years BP dated ( Tortonian ) and thus seems clearly older than the Quixaba lineup to be. Perhaps it represents an equivalent of Remédios lineup represents a peculiarity of the formation are very beautiful Duniteinschlüsse.

Note: Not all scientific authors acknowledge this K-Ar age and refer to irregularities in dating. For Schwab and block as well as integrating the basanites are attributed rather to the Quixaba lineup.

After completion of the Quixaba lineup producing volcanic activities took place in the Pleistocene erosion again. It came to the emergence of extensive Abrasionsplattformen, especially on the main island. The sea level changes during the Pleistocene left on these platforms sand and gravel deposits of the beach area, Kalkalgenriffe and marine sands. The platform levels are located at 9, 12 and 30 meters above sea level, although the vast 30-meter level in the interior of the island will undoubtedly be the most important. During the upper pleistocene sea depth article which was 6 meters below the present level, there are extensive sandy beaches formed in the south and southeast of the archipelago. The southeast trade winds, wind-blown sand, up to 20 meters high dunes that established a cordon between the Ilha Rata and the Santo Antônio peninsula in the northeast of the main island. Not quite as long dunes formed on the main island and at the entrance to Praia Sueste.

After renewed sea-level rise in the Holocene dunes were partially flooded, non-affected areas hardened to Caracas calcarenite. This bright, cream-colored sediment is composed mainly of lime particles corallinaceae algae. Only a small fraction of the particles ( about subjacent, melanokraten Ankaratriten up to 25% incremental) comes from the volcanic rocks. The solidification of the diagonally layered Calcarenite depends on the progress of the Kalzitzementation. Upper layers of the Calcarenite contain from bird guano -derived calcium phosphates.

The volcanic rocks of Fernando de Noronha set similar to the volcanic rocks on Tristan da Cunha, Gough, Canary Islands, Saint Helena and Trindade a characteristic undersaturated alkaline magmas Differentiatonstrend dar. The SiO2 content of the sodium- stressed rocks varies between 34.4 % ( Melilithankaratrite ) and 60, 8 % ( Alkalitarchyte ). Among the oceanic volcanic islands is likely to Fernando de Noronha world's one of the alkaline volcanic provinces next pose. Strangely, the brighter, richer SiO2 Magmendifferentiate were promoted at the beginning ( Remédios Formation). Only after a hiatus, 5-6 million years ago, began the ultramafic volcanism Quixaba lineup.

Population

The main island has been inhabited for about 400 years and currently has about 5,000 inhabitants. The majority of them live in the main town of Vila dos Remédios.

Economy and Transport

Twenty years ago, the population was still living from fishing and agriculture. Today, this area has fewer than 100 people. Much of the island's population is employed in the tourism sector. The island is advertised as one of the world's best places for diving.

There are daily flights to Recife and Natal.

History

The archipelago mentioned Amerigo Vespucci in 1503 for the first time. As a result, the French and the Dutch came to the islands, but finally won the Portuguese dominion. Both Portugal and Brazil used the island long as a penal colony. During World War II, American soldiers briefly came to the island. Then came under the islands until 1987, the Brazilian military. Since then, the establishment of a " soft tourism " begins. Most of the smaller islands and an area of ​​about 8 square kilometers on the main island are as Marine National Park of Fernando de Noronha, a nature reserve since 1988. Including marine protected area, the park covers 112.7 km ². In 2001 he was declared together with the Rocas Atoll by the UNESCO World Heritage Site.