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Red Sea

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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 0.5 m (1.6 ft) and are governed all by wind. In summer NW winds drive surface water south for about four months at a velocity of 15–20 cm/s (6–8 in/s)., 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/s (20–23.6 in/s) with a maximum of 1 m/s ([convert: unit mismatch]). at the mouth of the al-Kharrar Lagoon. However, the range of north-northeast current along the Saudi coast is 8–29 cm/s (3–11.4 in/s).

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 7 km/h (4.3 mph) and 12 km/h (7.5 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

Dust storm over the Red Sea

The Red Sea was formed by Arabia splitting from Africa due to movement of the Red Sea Rift. 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).

Sometimes 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:

Today surface water temperatures remain relatively constant at 21–25 °C (70–77 °F) and temperature and visibility remain good to around 200 m (656 ft), but the sea is known for its strong winds and unpredictable 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. Lack of significant rivers or streams draining into the sea.
  3. Limited connection with the Indian Ocean, which has 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

Red Sea coral and marine fish

The Red Sea is a rich and diverse ecosystem. More than 1200 species of fish[1] have been recorded in the Red Sea, and around 10% of these are found nowhere else.[2] This also includes 42 species of deepwater fish.[1] The rich diversity is in part due to the 2,000 km (1,240 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 (Red Sea) 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: see Red Sea species hazardous to humans.[3]

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:
Nanofossils, 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.

Security

The Red Sea is part of the sea roads between Europe, the Persian Gulf and East Asia, and as such has heavy shipping traffic. Piracy in Somalia occurs principally near the area of the Gulf of Aden south of the sea. Government-related bodies with responsibility to police the Red Sea area include the Port Said Port Authority, Suez Canal Authority and Red Sea Ports Authority of Egypt, Jordan Maritime Authority, Israel Port Authority, Saudi Ports Authority and Sea Ports Corporation of Sudan.

Facts and figures

  • Length: ~2,250 km (1,398.1 mi) - 79% of the eastern Red Sea with numerous coastal inlets
  • Maximum Width: ~ 306–355 km (190–220 mi)– Massawa (Eritrea)
  • Minimum Width: ~ 26–29 km (16–18 mi)- Bab el Mandeb Strait (Yemen)
  • Average Width: ~ 280 km (174.0 mi)
  • Average Depth: ~ 490 m (1,607.6 ft)
  • Maximum Depth: ~2,211 m (7,253.9 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 50 m (164 ft) deep.
  • About 15% of the Red Sea is over 1,000 m (3,300 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 ~500 m (1,640 ft)*)
  • Centre of Red Sea has a narrow trough (~ 1,000 m (3,281 ft)*; some deeps may exceed 2,500 m (8,202 ft)*)

Tourism

The sea is known for its spectacular recreational diving sites, such as Ras Mohammed, SS Thistlegorm (shipwreck), Elphinstone, The Brothers, Dolphin Reef and Rocky Island in Egypt 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 El Gouna, Hurghada, Safaga, Marsa Alam, on the western shore of the Red Sea, and Sharm-El-Sheikh, Dahab, and Taba on the Egyptian side of Sinaï, as well as Aqaba in Jordan and Eilat in Israel in an area known as the Red Sea Riviera.

Tourism in the South of Red Sea is presently considered risky because of the presence of pirates originating from uncontrolled zones of Somalia. Large vessels such as cargoes are sometimes attacked by high-speed boats heavily armed. The situation is even worse in the Gulf of Aden between Somalia and Yemen.

Bordering countries

Bordering countries are:

Towns and cities

Towns and cities on the Red Sea coast include:

See also

References

  1. ^ a b Froese, Ranier (2009). "FishBase". Retrieved 2009-03-12. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ Siliotti, A. (2002). Verona, Geodia (ed.). Fishes of the red sea. ISBN 88-87177-42-2.
  3. ^ Lieske, E. and Myers, R.F. (2004) Coral reef guide; Red Sea London, HarperCollins ISBN 0-00-715986-2

Further reading

  • Hamblin, W. Kenneth; Christiansen, Eric H. (1998), Earth's Dynamic Systems (8th ed.), Upper Saddle River: Prentice-Hall, ISBN 0137453736 {{citation}}: Unknown parameter |lastauthoramp= ignored (|name-list-style= suggested) (help).
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