Red Sea

 

ancient Sinus Arabicus or Erythraean Sea, narrow sea, c.170,000 sq mi (440,300 sq km), c.1,450 mi (2,330 km) long and up to 225 mi (362 km) wide, between Africa (Egypt, Sudan, and Eritrea) and the Arabian peninsula (Saudi Arabia and Yemen); a part of the Great Rift Valley. The Gulf of Aqaba and the Gulf of Suez are the sea's northern arms; between them is the Sinai peninsula. The Red Sea is linked with the Gulf of Aden and the Arabian Sea by the straits of Bab el Mandeb. The flat coastal plains of the Red Sea slope gradually to the submarine central trough, more than 7,000 ft (2,134 m) deep. The sea is dotted with islands (the largest group is the Dahlak Archipelago in the southwest) and with dangerous coral reefs. It is surrounded by exceedingly hot and dry deserts and steppes; the summer water temperature exceeds 85°F (29°C), and the water has a high salt content. The Red Sea was an important trade route in antiquity. Its importance declined with the discovery of an all-water route around Africa in 1498. The opening of the Suez Canal in 1869 made the Red Sea one of the chief shipping routes connecting Europe with East Asia and Australia. The closing of the canal after the 1967 Arab-Israeli War, the building of pipelines to the Mediterranean Sea, and the construction of supertankers too large for the canal diminished the sea's importance as a commercial artery, especially for petroleum. In 1975, however, the canal was reopened and enlarged, and traffic through the sea increased. Suez, Egypt; Elat, Israel; Jidda, Saudi Arabia; Hodeida, Yemen; Massawa, Eritrea; and Port Sudan, Sudan, are the main ports on the Red Sea and its northern arms.

This article is about the body of water. For other meanings see Red Sea (disambiguation).

The Red Sea is an inlet of the Indian Ocean between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb sound and the Gulf of Aden. In the north are 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 about 174,000 square miles (450,000 km²): being roughly 1,200 miles (1,900 km) long and, at its widest point, over 190 miles (300 km) wide. It has a maximum depth of 8,200 feet (2,500 m) in the central median trench and an average depth of 1,640 feet (500 m), but there are also extensive shallow shelves, noted for their marine life and corals. The sea is the habitat of over 1,000 invertebrate species and 200 soft and hard corals and is the world's most northern tropical sea.

The Red Sea is one of the most saline water bodies in the world, due to the effects of the water circulation pattern, resulting from evaporation and wind stress. Salinity ranges between 3.6 and 3.8%.

Name

Red Sea is a direct translation of the Greek Erythra Thalassa (Ερυθρά Θάλασσα), Latin Mare Rubrum, Arabic Al-Baḥr Al-Aḥmar (البحر الأحمر), and Tigrinya Qeyḥ bāḥrī (ቀይሕ ባሕሪ).

The name of the sea may signify the seasonal blooms of the red-coloured cyanobacteria Trichodesmium erythraeum near the water surface. Some suggest that it refers to the mineral-rich red mountains nearby which are called Harei Edom (הרי אדום). Edom, meaning "ruddy complexion", is also an alternative Hebrew name for the red-faced biblical character Esau (brother of Jacob), and the nation descended from him, the Edomites, which in turn provides yet another possible origin for Red Sea.^{[citation needed]}

Another hypothesis is that the name comes from the Himyarite, a local group whose own name means red.^{[citation needed]}

Yet another theory favored by some modern scholars is that the name red is referring to the direction south, the same way the Black Sea's name may refer to north. The basis of this theory is that some Asiatic languages used color words to refer to the cardinal directions^{[citation needed]}. Herodotus on one occasion uses Red Sea and Southern Sea interchangeably.^[1]

A final theory suggests that it was named so because it borders the Egyptian Desert which the ancient Egyptians called the Dashret or "red land"; therefore it would have been the sea of the red land.^{[citation needed]}

The association of the Red Sea with the Biblical account of the Exodus, in particular in the Passage of the Red Sea, goes back to the Septuagint translation of the book of Exodus from Hebrew into Koine, in which Hebrew Yam suph (ים סוף), meaning Reed Sea, is translated as Erythra Thalassa (Red Sea). Yam Suph is also the name for the Red Sea in modern Hebrew.

History

The Egyptians were the first to attempt a mission of exploration in the Red Sea.

The Bible, in the book of Exodus, famously tells the story of how Moses leads the Israelites across its headwaters, (presumably the Reed Sea which has since disappeared because of the Suez Canal water diversion) to freedom, by using the powers of God to part the waters. There is no extant archaeological evidence to support this claim. The common misinterpretation of y'am Suf is the Red Sea, so people thought Moses crossed the Red Sea. If this really happened, they really crossed the Reed Sea, the real meaning of y'am Suf.

It was a Greek sailor, Hippalus, who conferred an international dimension upon the Red Sea in his manifesto on the voyage of the Eritrea Sea and thus opened it up to an immense and exclusive trade with Asia. It was only from the 15th century onwards that Europe began to show interest in this area. In 1798, France charged General Bonaparte with invading Egypt and capturing the Red Sea. Although he failed in his mission, the engineer J.B. Lepere, who took part in it revitalised the plan for a canal which had been envisaged during the reign of the Pharaohs. The Suez Canal was opened in November 1869. At the time, the British, French, and Italians shared the trading posts. The posts were gradually dismantled following the First World War. After the Second World War, the Americans and Soviets exerted their influence whilst the volume of oil tanker traffic intensified. However, the Six Day War culminated in the closure of the Suez Canal from 1967 to 1975. Still today, in spite of patrols by the major maritime fleets in the waters of the Red Sea, the Suez Canal has never recovered its supremacy over the Cape route, which is believed to be less vulnerable.

Oceanography

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 and cold water in the north and relatively hot water in the south.

Climate: 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  °C ( °F) in the north and  °C ( °F) in the south, with only about 2 °C (3.6 °F) variation during the winter months. The overall average water temperature is  °C ( °F). The rainfall over the Red Sea and its coasts is extremely low averaging  m ( 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  cm ( in) per year and high salinity with minimal seasonal variation.

Salinity: The Red Sea is one of the most saline water bodies in the world, due to the effects of the water circulation pattern, resulting from evaporation and wind stress. Salinity ranges between 3.6 and 3.8%.

Tidal range: In general tide ranges between  m ( ft) in the north, near the mouth of the Gulf of Suez and  m ( ft) in the south near the Gulf of Aden but it fluctuates between  m ( ft) and  m ( ft) away from the nodal point. The central Red Sea (Jeddah area) is therefore almost tideless, and as such the annual water level changes are more significant. Because of the small tidal range the water during high tide inundates the coastal sabkhas as a thin sheet of water up to a few hundred meters rather than inundating the sabkhas through a network of channels. However, south of Jeddah in the Shoiaba area the water from the lagoon may cover the adjoining sabkhas as far as  km ( mi) whereas, north of Jeddah in the Al-kharrar area the sabkhas are covered by a thin sheet of water as far as  km ( mi). The prevailing north and northeastern winds influence the movement of water in the coastal inlets to the adjacent sabkhas, especially during storms. Winter mean sea level is  m ( ft) higher than in summer. Tidal velocities passing through constrictions caused by reefs, sand bars and low islands commonly exceed 1-2 metres per second (3–6.5 ft/s).

Current: In the Red Sea detailed current data is lacking, partially because they are weak and variable both spatially and temporally. Temporal and spatial currents variation is as low as  m ( ft) and are governed mostly by wind. In summer NW winds drive surface water south for about four months at a velocity of 15-20 cm per second (6–8 in/sec)., whereas in winter the flow is reversed resulting in the inflow of water from the Gulf of Aden into the Red Sea. The net value of the latter predominates, resulting in an overall drift to the northern end of the Red Sea. Generally the velocity of the tidal current is between 50-60 cm per second (20–23.6 in/sec) with a maximum of  m ( ft) per sec. at the mouth of the al-Kharrar Lagoon. However, the range of north-northeast current along the Saudi coast is 8-29 cm per second (3–11.4 in/sec).

Wind Regime: With the exception of the northern part of the Red Sea, which is dominated by persistent north-west winds, with speeds ranging between  km/h ( mph) and  km/h ( mph)., the rest of the Red Sea and the Gulf of Aden are subjected to the influence of regular and seasonally reversible winds. The wind regime is characterized by both seasonal and regional variations in speed and direction with average speed generally increasing northward.

Wind is the driving force in the Red Sea for transporting the material either as suspension or as bedload. Wind induced currents play an important role in the Red Sea in initiating the process of resuspension of bottom sediments and transfer of materials from sites of dumping to sites of burial in quiescent environment of deposition. Wind generated current measurement is therefore important in order to determine the sediment dispersal pattern and its role in the erosion and accretion of the coastal rock exposure and the submerged coral beds.

Geology

The Red Sea formed by Arabia splitting from Africa due to plate tectonics. This split started in the Eocene and accelerated during the Oligocene. The sea is still widening and it is considered that the sea will become an ocean in time (as proposed in the model of John Tuzo Wilson).

Sometime during the Tertiary period the Bab el Mandeb closed and the Red Sea evaporated to an empty hot dry salt-floored sink. Effects causing this would be:-

• A "race" between the Red Sea widening and Perim Island erupting filling the Bab el Mandeb with lava.
• The lowering of world sea level during the Ice Ages due to much water being locked up in the ice caps.

Today surface water temperatures remain relatively constant at 70–77 °F (21–25 °C) and temperature and visibility remain good to around 660 feet (200 m), but the sea is known for its strong winds and tricky local currents.

In terms of salinity, the Red Sea is greater than the world average, approximately 4 percent. This is due to several factors: 1) high rate of evaporation and very little precipitation, 2) a lack of significant rivers or streams draining into the sea, and 3) limited connection with the Indian Ocean (and its lower water salinity).

A number of volcanic islands rise from the center of the sea. Most are dormant, but in 2007, Jabal al-Tair island erupted violently.

Living resources

The Red Sea is a rich and diverse ecosystem. More than 1100 species of fish^[2] have been recorded in the red sea, and around 10% of these are found nowhere else.^[3] This also includes around 75 species of deepwater fish.^[2] The rich diversity is in part due to the  km ( mi) of coral reef extending along its coastline; these fringing reefs are 5000-7000 years old and are largely formed of stony acropora and porites corals. The reefs form platforms and sometimes lagoons along the coast and occasional other features such as cylinders (such as the blue hole at Dahab). These coastal reefs are also visited by pelagic species of red sea fish, including some of the 44 species of shark.

The special biodiversity of the area is recognised by the Egyptian government, who set up the Ras Mohammed National Park in 1983. The rules and regulations governing this area protect local wildlife, which has become a major draw for tourists, in particular for diving enthusiasts.

Divers and snorkellers should be aware that although most Red Sea species are innocuous, a few are hazardous to humans.^[4]

Other marine habitats include sea grass beds, salt pans, mangroves and salt marshes.

Mineral resources

In terms of mineral resources the major constituents of the Red Sea sediments are as follows:

• Biogenic constituents:

Nannofossils, foraminifera, pteropods, siliceous fossils

• Volcanogenic constituents:

Tuffites, volcanic ash, montmorillonite, cristobalite, zeolites

• Terrigenous constituents:

Quartz, feldspars, rock fragments, mica, heavy minerals, clay minerals

• Authigenic minerals:

Sulfide minerals, aragonite, Mg-calcite, protodolomite, dolomite, quartz, chalcedony.

• Evaporite minerals:

Magnesite, gypsum, anhydrite, halite, polyhalite

• Brine precipitate:

Fe-montmorillonite, goethite, hematite, siderite, rhodochrosite, pyrite, sphalerite, anhydrite.

Desalination plants

There is extensive demand of desalinated water to meet the requirement of the population and the industries along the Red Sea.

There are at least 18 desalination plants along the Red Sea coast of Saudi Arabia which discharge warm brine and treatment chemicals (chlorine and anti-scalants) that may cause bleaching and mortality of corals and diseases to the fish stocks. Although this is only a localized phenomenon, it may intensify with time and have a profound impact on the fishing industry.

The water from the Red Sea is also utilized by oil refineries and cement factories for cooling purposes. Used water drained back into the coastal zones may cause harm to the nearshore environment of the Red Sea.

Facts and figures at a glance

• Length: ~ km ( mi) - 79% of the eastern Red Sea with numerous coastal inlets

• Maximum Width: ~ 306–354 km (190–220 mi)– Massawa (Eritrea)
• Minimum Width: ~ 26–29 km (16–18 mi)- Bab el Mandeb Strait (Yemen)
• Average Width: ~  km ( mi)
• Average Depth: ~  m ( ft)
• Maximum Depth: ~ m ( ft)
• Surface Area: 438-450 x 10² km² (16,900–17,400 sq mi)
• Volume: 215–251 x 10³ km³ (51,600–60,200 cu mi)

• Approximately 40% of the Red Sea is quite shallow (under 100 m/330 ft), and about 25% is under  m ( ft) deep.
• About 15% of the Red Sea is over  m ( ft) depth that forms the deep axial trough.
• Shelf breaks are marked by coral reefs
• Continental slope has an irregular profile (series of steps down to ~ m/ ft)
• Centre of Red Sea has a narrow trough (~  m/ ft; some deeps may exceed  m/ ft)

Some of the research cruises in the Red Sea

Numerous research cruises have been conducted:

• Arabia Felix (1761-1767)
• Vitiaz (1886-1889)
• Valdivia (1898-1894)
• Pola (1897-98) Southern Red Sea and (1895/96 – Northern Red Sea
• Ammiraglio Magnaghi (1923/24)
• Snellius (1929 –1930)
• Mabahiss (1933-1934 and 1934-1935)
• Albatross (1948)
• Manihine (1849 and 1952)
• Calypso (1955)
• Atlantis and Vema (1958)
• Xarifa (1961)
• Meteor (1961)
• Glomar Challenger (1971)
• Sonne (1997)
• Meteor (1999)

Tourism

The sea is known for its spectacular dive sites such as Ras Mohammed, SS Thistlegorm (ship wreck), Elphinstone, The Brothers and Rocky Island in Egypt, Dolphin Reef in Eilat, Israel and less known sites in Sudan such as Sanganeb, Abington, Angarosh and Shaab Rumi (see photo above).

The Red Sea became known a sought-after diving destination after the expeditions of Hans Hass in the 1950s, and later by Jacques-Yves Cousteau. Popular tourist resorts include Sharm-El-Sheikh and Hurghada (and recently Marsa Alam) and Dahab in Egypt, as well as Eilat, Israel in an area known as the Red Sea Riviera.

Bordering countries

Bordering countries are:

• Northern shore:
  • Egypt
  • Israel
  • Jordan
• Western shore:
  • Sudan
  • Egypt
  • Eritrea
• Eastern shore:
  • Saudi Arabia
  • Yemen
• Southern shore:
  • Djibouti
  • Eritrea
  • Somaliland

Towns and cities

Towns and cities on the Red Sea coast include:

Aqaba (العقبة) Arkiko (ሕርጊጎ) Asseb (ዓሳብ) Dahab (دهب) Eilat (אילת) Hala'ib (حلايب)

Al Hudaydah (الحديدة) Hurghada (الغردقة) Jeddah (جدة) Marsa Alam (مرسى علم) Massawa (ምጽዋ) Nuweiba (نويبع)

Port Safaga (ميناء سفاجا) Port Sudan (بورت سودان) Sharm el Sheikh (شرم الشيخ) Soma Bay (سوما باي) Suakin (سواكن) El Suweis (السويس)

Taba (طابا) El-Tor (الطور) Yanbu (ينبع) Saylac Berbera Mayd & Hees

References

1. ^ Schmitt 1996
2. ^ ^{a b} FishBase. Ed. Ranier Froese and Daniel Pauly
3. ^ Siliotti, A. (2002) fishes of the red sea Verona, Geodia ISBN 88-87177-42-2
4. ^ Lieske, E. and Myers, R.F. (2004) Coral reef guide; Red Sea London, HarperCollins ISBN 0-00-715986-2

• Hamblin, W. Kenneth, and Eric H. Christiansen. Earth's Dynamic Systems, 8th ed. Upper Saddle River: Prentice-Hall, Inc., 1998. ISBN 0-13-745373-6

See also

• Red Sea travel guide from Wikitravel
• Red Sea Riviera
• Suez Canal
• Robert Moresby
• Passage of the Red Sea
• Periplus of the Erythraean Sea
• M/V al-Salam Boccaccio 98 ferry disaster

Coordinates: 22°00′N, 38°00′Enrm:Rouoge Mé

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