Minggu, 21 Oktober 2012


The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez (leading to the Suez Canal). The Red Sea is a Global 200 ecoregion.

Occupying a part of the Great Rift Valley, the Red Sea has a surface area of roughly 438,000 km² (169,100 square miles ).It is about 2250 km (1398 miles) long and, at its widest point, is 355 km (220.6 miles) wide. It has a maximum depth of 2211 metres (7254 feet) in the central median trench, and an average depth of 490 metres (1,608 feet).

The Red Sea lies between arid land, desert and semi-desert. The main reasons for the better development of reef systems along the Red Sea is because of its greater depths and an efficient water circulation pattern, The Red Sea water mass exchanges its water with the Arabian Sea, Indian Ocean via the Gulf of Aden. These physical factors reduce the effect of high salinity caused by evaporation water in the north and relatively hot water in the south.
The climate of the Red Sea is the result of two distinct monsoon seasons; a northeasterly monsoon and a southwesterly monsoon. Monsoon winds occur because of the differential heating between the land surface and sea. Very high surface temperatures coupled with high salinities makes this one of the hottest and saltiest bodies of seawater in the world. The average surface water temperature of the Red Sea during the summer is about 26 °C (79 °F) in the north and 30 °C (86 °F) in the south, with only about 2 °C (3.6 °F) variation during the winter months. The overall average water temperature is 22 °C (72 °F). Today surface water temperatures remain relatively constant at 21–25 °C (70–77 °F). Temperature and visibility remain good to around 200 m (656 ft). The sea is known for its strong winds and unpredictable local currents.

The rainfall over the Red Sea and its coasts is extremely low, averaging 0.06 m (2.36 in) per year. The rain is mostly in the form of showers of short spells, often associated with thunderstorms and occasionally with dust storms. The scarcity of rainfall and no major source of fresh water to the Red Sea result in the excess evaporation as high as 205 cm (81 in) per year and high salinity with minimal seasonal variation. A recent underwater expedition to the Red Sea offshore from Sudan and Eritrea[14] found surface water temperatures 28 °C in winter and up to 34 °C in the summer, but despite that extreme heat the coral was healthy with much fish life with very little sign of coral bleaching, with only 9% infected by thalassomonas loyana, the 'white plague' agent. Favia favus coral there harbours a virus, BA3, which kills T.loyana.[15] Plans are afoot to use samples of these corals' apparently heat-adapted commensal algae to salvage bleached coral elsewhere.

Published : en.wikipedia.org

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