Friday, March 19, 2010

Cap-Vert

Cap-Vert is a peninsula in Senegal, and the westernmost part of the continent of Africa. Originally called Cabo Verde or "Cape Green" by Portuguese explorers, it is not to be confused with the Cape Verde islands, which are some 560 kilometres further west. Dakar, the capital of Senegal, is located near the southern tip.
Cap-Vert is a rocky promontory extending west from the main sandy areas of Senegal. Cap-Vert has an excellent harbor, facing Gorée Island.
Formed by a combination of volcanic offshore islands and a land bridge produced by coastal currents, it projects into the Atlantic Ocean, bending back to the southeast at its tip. Exposure to southwesterly winds contributes to Cape Verde's seasonal verdant appearance, in contrast to the undulating yellow dunes to the north.
The peninsula is shaped like a triangle , with the base of the triangle roughly along the north and its apex on the south, near Dakar. Near Pointe des Almadies, the north-western tip of the cape, lies Dakar's international airport, famous as a transatlantic ferrying point during World War II. Twin volcanic cones, the Deux Mamelles ("Two Teats"), dominate the landscape along the coast northwest of Dakar. The peninsula embraces a bay and a natural harbour in the southwest.
The indigenous inhabitants of the peninsula, the Lebou, lived as fishermen and farmers. Since about 1444, when the Portuguese first sighted the cape, it has been an entrepôt for African-European trade. The French later established the city of Dakar on the cape in 1857.

The Cape Verde archipelago is located approximately 604 kilometres off the coast of West Africa. It is composed of ten islands and eight islets. The islands have a combined size of just over 4,000 square kilometers.[11] The islands are divided into the Barlavento islands (Santo Antão, São Vicente, Santa Luzia, São Nicolau, Sal, and Boa Vista) and the Sotavento islands .The largest island, both in size and population, is Santiago, where the capital of Praia is located.


Though Cape Verde's islands are all volcanic in origin, they vary widely in terrain. A still-active volcano on the island of Fogo is the highest point on the archipelago. Extensive salt flats are found on Sal and Maio. On Santiago, Santo Antão, and São Nicolau, arid slopes give way in places to sugarcane fields or banana plantations spread along the base of towering mountains.
Cape Verde’s climate is milder than that of the African mainland; because the island is surrounded by the sea, temperatures are generally moderate. Average daily high temperatures range from 25 °C in January to 29 °C in September. Cape Verde is part of the Sahelian arid belt, with nothing like the rainfall levels of nearby West Africa. It does rain irregularly between August and October, with frequent brief-but-heavy downpours. A desert is usually defined as terrain which receives less than 250 mm of annual rainfall. Cape Verde's total is slightly above this criterion, which makes the area climate semi-desert.
Cape Verde's isolation has resulted in the islands having a number of endemic species, particularly bird and reptiles, many of which are endangered by human development. Endemic birds include Alexander's Swift , Bourne's Heron , the Raso Lark , the Cape Verde Warbler , and the Iago Sparrow . The islands are also an important breeding area for seabirds including the Cape Verde Shearwater. Reptiles include the Cape Verde Giant Gecko.
The islands are geologically principally composed of igneous rocks, with basic volcanics and pyroclastics comprising the majority of the total volume. The volcanic and plutonic rocks are distinctly basic in character. The archipelago is an example of a soda-alkaline petrographic province, with a petrologic succession which is similar to that found in other Mid Atlantic islands. Mount Fogo is an active volcano which most recently erupted in 1995. Fogo’s caldera is 8 km in diameter, the rim is at an elevation of 1600 m with an interior cone rising to 2830 m from the crater's floor level. Calderas probably result from the subsidence, following the partial evacuation of the magma chamber, of a cylindrical block into the supplying magma chamber, in this case lying at a depth of some 8 km. The archipelago has been dated at approximately 180 million years old.
Hurricanes that form near the Cape Verde Islands are sometimes referred to as Cape Verde-type hurricanes. These hurricanes can become very intense as they cross warm Atlantic waters.

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