:''This article is about the body of water. For other meanings see
Red Sea (disambiguation).''
Location of the Red Sea
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'' (),
Latin ''Mare Rubrum'',
Arabic ''Al-Baḥr Al-Aḥmar'' (البحر الأحمر), and
Tigrinya ''Qeyḥ bāḥrī'' (ቀይሕ ባሕሪ).
The name of the sea does not indicate the color of the water since it is not red. It may signify the seasonal blooms of the red-colored
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''.
Another hypothesis is that the name comes from the
Himyarite, a local group whose own name means ''red''.
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.
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.
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.
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 26°C in the north and 30°C in the south, with only about 2°C variation during the winter months. The overall average water temperature is 22°C. The
rainfall over the Red Sea and its coasts is extremely low averaging 0.06 m 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 per yr 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 0.6 m in the north, near the mouth of the Gulf of Suez and 0.9 m in the south near the Gulf of Aden but it fluctuates between 0.20 and 0.30 m 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 3 km whereas, north of Jeddah in the Al-kharrar area the sabkhas are covered by a thin sheet of water as far as 2 km. 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 0.5 m higher than in summer. Tidal velocities passing through constrictions caused by reefs, sand bars and low islands commonly exceed 1-2 m per sec.
'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 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 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 sec with a maximum of 1 m 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 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 7 and 12 km per hr., 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 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).
Living resources
Red Sea coral and marine fish
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.
The rich diversity is in part due to the 2000 km 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 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
The Red Sea water is an essential asset. 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: ~1900 km - 79% of the eastern Red Sea with numerous coastal inlets
:
★ Maximum Width: ~ 306–354 km – Massawa (Eritrea)
:
★ Minimum Width: ~ 26–29 km -
Bab el Mandeb Strait (Yemen)
:
★ Average Width: ~ 280 km
:
★ Average Depth: ~ 490 m
:
★ Maximum Depth: ~2850 m
:
★ Surface Area: 438-450 x 10² km²
:
★ Volume: 215–251 x 10³ km³
:
★ Approximately 40% of the Red Sea is quite shallow (under 100 m), and about 25% is under 50 m deep.
:
★ About 15% of the Red Sea is over 1000 m 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)
:
★ Centre of Red Sea has a narrow trough (~ 1000 m; some deeps may exceed 2500 m)
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
Towns and cities
Towns and cities on the Red Sea coast include:
References
1. Schmitt 1996
2. 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 Riviera
★
Suez Canal
★
Robert Moresby
★
Passage of the Red Sea
★
Periplus of the Erythraean Sea
★
M/V al-Salam Boccaccio 98 ferry disaster
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