The
Red Sea (Arabic:
البحر الأحمر al-Baħr al 'Aħmar, Hebrew: ים סוף Yam Suph) 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. The water is not red, as
the name may imply.
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 meters (7254 feet)
in the central median trench, and an average depth of 490 meters
(1,608 feet). However, 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. It is the world's northernmost tropical sea.
Name
Red Sea is a direct translation of the
Greek Erythra Thalassa ( ),
Latin Mare Rubrum (but also
Sinus
Arabicus, i.e., the Arabian Gulf),
Arabic {{Unicode|
Al-Baḥr Al-Aḥmar
(البحر الأحمر), and
Tigrinya
Qeyyiḥ bāḥrī.
The name of the sea may signify the seasonal blooms of the
red-coloured
Trichodesmium
erythraeum near the water's surface.
Another hypothesis is that the name comes from the
Himyarite, a local group whose own name means
red.
A theory
favored by some modern scholars is that the name red is
referring to the direction South, just as 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.
It is theorized 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 Israelite
Crossing of the Red Sea is ancient,
and was made explicit in the
Septuagint
translation of the
Book of Exodus
from
Hebrew to
Koine
Greek in approximately the third century B.C. In that version,
the Hebrew
Yam Suph (ים סוף) is
translated as
Erythra Thalassa (Red Sea). (See also the
more recent suggestion that the
Yam Suph of the Exodus
refers to a
Sea of Reeds).
The Red
Sea is one of four seas named in English after common color terms — the others being the Black Sea, the White
Sea
and the Yellow Sea
.
The direct
rendition of the Greek Erythra Thalassa in Latin as
Mare Erythraeum refers to the
north-western part of the Indian Ocean, and also to a region on Mars.
History
The earliest known exploration of the Red Sea was conducted by
Ancient Egyptians, as they attempted
to establish commercial routes to
Punt.
One such expedition took place around 2500 BC, and another around
1500 BC. Both involved long voyages down the Red Sea.
The Biblical
Book of Exodus tells the
story of the
Israelites' miraculous
crossing of a body of water,
which the Hebrew text calls
Yam
Suph. Yam Suph is traditionally identified as the Red Sea.
The account is part of the Israelites'
escape
from slavery in Egypt.
Yam Suph can also been
translated as
Sea of Reeds, which draws
doubts upon the claim that the Crossing of the Red Sea actually
occurred on the Red Sea.
In the 6th century BC,
Darius
the Great of
Persia sent
reconnaissance missions to the Red Sea, improving and extending
navigation by locating many hazardous rocks and currents.
A canal
was built between the Nile and the northern end
of the Red Sea at Suez
. In
the late 4th century BC,
Alexander
the Great sent Greek naval expeditions down the Red Sea to the
Indian Ocean. Greek navigators continued to explore and compile
data on the Red Sea.
Agatharchides
collected information about the sea in the 2nd century BC. The
Periplus of the
Erythraean Sea, written sometime around the 1st century AD,
contain a detailed description of the Red Sea's ports and sea
routes. The Periplus also describes how
Hippalus first discovered the direct route from the
Red Sea to India.
The Red Sea was favored for
Roman
trade with India starting with the reign of
Augustus, when the
Roman
Empire gained control over the Mediterranean, Egypt, and the
northern Red Sea. The route had been used by previous states but
grew in the volume of traffic under the Romans. From Indian ports
goods from China were introduced to the Roman world. Contact
between Rome and China depended on the Red Sea, but the route was
broken by the
Aksumite Empire around
the 3rd century AD.
During the
Middle Ages, the Red Sea was
an important part of the
Spice trade
route.
In 1798,
France
ordered General Bonaparte
to invade Egypt and take control of 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. Several canals were built in ancient
times from the Nile to the Red Sea along or near the line of the
present
Sweetwater Canal, but none
lasted for long.
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.
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
Bathymetric map of the Red Sea
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 in the north and in the south, with only about 2 °C (3.6
°F) variation during the winter months. The overall average water
temperature is . The
rainfall over the Red
Sea and its coasts is extremely low averaging 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 per year and high salinity with minimal seasonal variation.
A recent
underwater expedition to the
Red Sea offshore from Sudan
and Eritrea
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, and there were plans to use
samples of these corals' apparently heat-adapted commensal algae to salvage
bleached coral elsewhere.
Salinity
The Red Sea is one of the most saline bodies of water in the world,
due to high evaporation.
Salinity ranges from between ~36 (ppt) in
the southern part due to the effect of the Gulf of Aden water and reaches 41 (ppt) in the northern part,
due mainly to the Gulf of
Suez water and the high evaporation. The average
salinity is 40 (ppt).
Tidal range
In general tide ranges between in the north, near the mouth of the
Gulf of Suez and in the south near the Gulf of Aden but it
fluctuates between and 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 whereas,
north of Jeddah in the Al-kharrar area the sabkhas are covered by a
thin sheet of water as far as . 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 higher than in summer. Tidal velocities passing
through constrictions caused by reefs, sand bars and low islands
commonly exceed 1–2 m/s (3–6.5 ft/s).Coral reefs in the Red
Sea are near Egypt, Saudi Arabia, Israel and Sudan.
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 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 . 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 and ., 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 was 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).
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:
- High rate of evaporation and very little precipitation.
- Lack of significant rivers or streams draining into the
sea.
- 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 have been recorded
in the Red Sea, and around 10% of these are found nowhere else.
This also includes 42 species of
deepwater fish. The
rich diversity is in part due to the 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: see
Red Sea species
hazardous to humans.
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:
- Nanofossils, foraminifera, pteropods, siliceous fossils
- Volcanogenic constituents:
- Tuffites, volcanic
ash, montmorillonite, cristobalite, zeolites
- Terrigenous constituents:
- Quartz, feldspars, rock fragments, mica, heavy minerals, clay
minerals
- Sulfide minerals, aragonite, Mg-calcite,
protodolomite, dolomite, quartz, chalcedony.
- Magnesite, gypsum, anhydrite, halite, polyhalite
- 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: ~ - 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: ~
- * Average Depth: ~
- * Maximum Depth: ~
- * 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 deep.
- * About 15% of the Red Sea is over 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 ~ )
- * Centre of Red Sea has a narrow trough (~ ; some deeps may
exceed )
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
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:
- Eastern shore:
- Northern shore:
- Southern shore:
- Western shore:
Towns and cities
Towns and cities on the Red Sea coast include:
See also
References
- 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
External links
erupting filling the Bab el
Mandeb with lava.
(الحديدة)
(القصير)
(العقبة)
(ዓሳብ)
(حلايب)
(ሕርጊጎ)
(جدة)
(ምጽዋ)
(نويبع)
(ميناء سفاجا)
(بورت سودان)
(رابغ)
(شرم الشيخ)
(سوما باي)
(سواكن)
(طابا)
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