Satellite image of the Bosporus, taken from the International Space Station in April 2004.
The
Bosphorus or
Bosporus (), also known as the
Istanbul Strait (), is a
strait that forms part of the boundary between the
European part of
Turkey (
Thrace) and its
Asian part (
Anatolia). It is one of the
Turkish Straits, along with the
Dardanelles. The world's narrowest strait used for
international navigation, it connects the
Black Sea with the
Sea of Marmara (which is connected by the
Dardanelles to the
Aegean Sea, and thereby to the
Mediterranean Sea). It is approximately long, with a maximum width of at the northern entrance, and a minimum width of between Kandilli and Aşiyan; and between Anadoluhisarı and Rumelihisarı. The depth varies from in midstream. The shores of the strait are heavily populated as the city of
Istanbul (with a metropolitan area in excess of 11 million inhabitants) straddles it.
Two
bridges cross the Bosporus. The first, the
Bosphorus Bridge, is long and was completed in 1973. The second,
Fatih Sultan Mehmet (Bosphorus II) Bridge, is long, and was completed in 1988 about north of the first bridge. Plans for a third road bridge, which will allow transit traffic to by-pass the city traffic, have been approved by the Ministry of Transportation. The bridge will be part of the "Northern Marmara Motorway", which will be further integrated with the existing Black Sea Coastal Highway. The location will be somewhere north of the existing two bridges, but the exact path is kept secret to prevent false rumour trading of lands on the possible routes.
Another crossing,
Marmaray, is a long undersea
railway tunnel currently under construction and is expected to be completed in 2012. Approximately of the tunnel will run under the strait, at a depth of about .
Associations
thumb|[[Ottoman Empire|Ottoman era
waterfront houses on the Bosporus.]]
The name comes from the
Greek word
Bosporos (
Βόσπορος).
[Entry: at Henry George Liddell, Robert Scott, 1940, A Greek-English Lexicon.] Its
etymology is from
bous (:
ox) and
poros (: "means of passing a river, ford, ferry") (the similar Ancient Greek word for "passage, strait" is
porthmos ()), thus meaning "oxen passage", which could reflect the older history of the region. The Greeks analysed it as "
ox-ford" or "shallow sea ox passage"
and associated it with the
myth of
Io's travels after Zeus turned her into an
heifer for her protection. It has also been thought to be a Thracian form of
Phôsphoros (
Φωσφόρος), "light-bearing", an epithet of the goddess
Hecate.
It is also said in myth that floating rocks known as the
Symplegades or Clashing Rocks once crushed any ship that attempted passage of the Bosporus until the hero
Jason obtained passage, whereupon the rocks became fixed, and Greek access to the Black Sea was opened.
Formation of the Bosporus
thumb|left|upright|A view of the Bosporus strait, with the Fatih Sultan Mehmet Bridge seen in the background.
The exact cause for the formation of the Bosporus remains the subject of vigorous debate among geologists. Thousands of years ago, the
Black Sea became disconnected from the
Aegean Sea. One recent theory (published in 1997 by
William Ryan and
Walter Pitman from
Columbia University) contends that the Bosporus was formed about 5600 BC when the rising waters of the Mediterranean/
Sea of Marmara breached through to the Black Sea, which at the time (according to the theory) was a low-lying body of fresh water.
Some have argued that the resulting massive flooding of the inhabited and probably farmed northern shores of the Black Sea is thought to be the historic basis for the
flood stories found in the
Epic of Gilgamesh and in the
Bible in
Book of Genesis, Chapters 6-9. On the other hand, there is also evidence for a flood of water going in the opposite direction, from the Black Sea into the Sea of Marmara around 7000 or 8000 BC.
Biblical reference
St.
Jerome's
Vulgate translates the Hebrew
besepharad in Obadiah, 1-20 as "Bosforus", but other translations give it as "
Sepharad" (probably
Sardis, but later identified with Spain).
Ancient Greece, Rome, the Byzantines and the Ottoman Empire
As the only passage between the Black Sea and the Mediterranean, the Bosporus has always been of great commercial and strategic importance. The Greek city-state of
Athens in the 5th century BC, which was dependent on grain imports from
Scythia, therefore maintained critical alliances with cities which controlled the straits, such as the
Megarian colony
Byzantium.
The strategic significance of the strait was one of the factors in the decision of the Roman Emperor
Constantine the Great to found there in 330 AD his new capital,
Constantinople, which came to be known as the capital of the
Eastern Roman Empire. On 29 May 1453 it was
conquered by the emerging
Ottoman Empire. In fact, as the Ottoman Turks closed in on Istanbul, they constructed a fortification on each side of the strait,
Anadoluhisarı (1393) and
Rumelihisarı (1451).
Strategic importance
The strategic importance of the Bosporus remains high, and control over it has been an objective of a number of hostilities in modern history, notably the
Russo–Turkish War, 1877–1878, as well as of the attack of the
Allied Powers on the
Dardanelles in 1915 in the course of
World War I.
Several international treaties have governed vessels using the waters. Following WW I, the 1920
Treaty of Sèvres demilitarized the strait and made it an international territory under the control of the
League of Nations. This was amended under the 1923
Treaty of Lausanne, which restored the straits to Turkish territorybut allowed all foreign warships and commercial shipping to traverse the straits freely. Turkey eventually rejected the terms of that treaty, and subsequently Turkey remilitarized the straits area. The reversion to this old regime was formalized under the
Montreux Convention Regarding the Regime of the Turkish Straits of July 1936. That convention, which is still in practical force as of 2008, treats the straits as an international shipping lane, but Turkey does retain the right to restrict the naval traffic of non-Black Sea nations (such as
Greece, a traditional enemy, or
Algeria).
During
World War II, through February 1945, when Turkey was neutral for most of the length of the conflict, the Dardanelles were closed to the ships of the belligerent nations. In the conferences during World War II, Soviet leader
Joseph Stalin openly requested the concession of Soviet military bases on the
Straits, even though Turkey was not involved in the war. This incident, coupled with Stalin's demands for the restitution of the Turkish provinces of
Kars,
Artvin and
Ardahan to the
Soviet Union (which were lost by Turkey with the Russo–Turkish War of 1877–1878, but were regained with the
Treaty of Kars in 1921) was one of the main reasons why Turkey decided to give up its general principle of neutrality in foreign affairs. Turkey did declare war against Germany in February 1945, but did not engage in offensive actions.
In more recent years, the Turkish Straits have become particularly important for the oil industry. Russian oil, from ports such as
Novorossyisk, is exported by tankers to western Europe and the U.S. via the Bosphorus and the Dardanelles straits.
Sightseeing
A cheap way to explore the Bosporus is offered by the public ferries that traverse the Bosporus from
Eminönü on the historic peninsula of Istanbul to Anadolu Kavağı near the Black Sea, zigzagging between the Rumelian and Anatolian sides of the city.
It is also possible to experience the Bosphorus by taking a regular ride in one of the public ferries that travel every 45 minutes between the European and the Asian sides. It is also possible to travel by the privately owned ferries available between
Üsküdar and
Beşiktaş.
There are also tourist rides available in various places along the coasts of the Bosphorus. The prices vary according to the type of the ride, and some feature loud popular music for the duration of the trip.
See also
