The Alboran Sea (from

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter ...

, ''al-Baḥrān'') is the westernmost portion of the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

, lying between the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, def ...

and the north of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

(Spain on the north and Morocco and Algeria on the south). The

Strait of Gibraltar The Strait of Gibraltar ( ar, مضيق جبل طارق, Maḍīq Jabal Ṭāriq; es, Estrecho de Gibraltar, Archaic: Pillars of Hercules), also known as the Straits of Gibraltar, is a narrow strait that connects the Atlantic Ocean to the Medi ...

, which lies at the west end of the Alboran Sea, connects the Mediterranean with the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

Geography

Its average depth is and maximum depth is . The

International Hydrographic Organization The International Hydrographic Organization (IHO) is an intergovernmental organisation representing hydrography. , the IHO comprised 98 Member States. A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters ...

defines the limits of the Alboran Sea as follows:

''On the West.'' The Eastern limit of the Strait of Gibraltar: A line joining from tip ( Europa Point) of '' Cap Gibraltar'' in Europe to the tip of the '' Península de Almina'' of
Ceuta Ceuta (, , ; ar, سَبْتَة, Sabtah) is a Spanish autonomous city on the north coast of Africa. Bordered by Morocco, it lies along the boundary between the Mediterranean Sea and the Atlantic Ocean. It is one of several Spanish territori ...
in Africa (). ''On the East.'' A line joining from ''
Cabo de Gata Cabo de Gata is a cape located in Níjar, Almería in the south of Spain, one of the biggest capes. It is the driest place in the Iberian Peninsula (150-170 mm average precipitation, being the lowest 52 mm in 1981). However, the area th ...
'' in
Andalusia Andalusia (, ; es, Andalucía ) is the southernmost autonomous community in Peninsular Spain. It is the most populous and the second-largest autonomous community in the country. It is officially recognised as a "historical nationality". The ...
in Europe to ''Cap Fegalo'', near
Oran, Algeria Oran ( ar, وَهران, Wahrān) is a major coastal city located in the north-west of Algeria. It is considered the second most important city of Algeria after the capital Algiers, due to its population and commercial, industrial, and cultural ...
in Africa ().

Several small islands dot the sea, including the eponymous Isla de Alborán. Most, even those close to the African shore, belong to Spain.

Geology

The Alboran domain, the seafloor beneath the Alboran Sea (known as the internal zones) together with the surrounding mountains (known as the external zones; the Gibraltar Arc and

Atlas Mountains The Atlas Mountains are a mountain range in the Maghreb in North Africa. It separates the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the name "Atlantic" is derived from the mountain range. It stretches around through ...

), is mostly made of

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial'' be ...

and marks the westernmost terminus of the

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its ow ...

s that were subducted between the African and

Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent an ...

s when the

Tethys Ocean The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

closed. Reoccurring earthquakes at a depth of about indicate that this

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

is ongoing and that complex interactions between the lithosphere and mantle are forming the region. The internal zones are made of Late Paleozoic to

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

rocks that were piled up during the Tertiary and has been extended since the Early

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. The seafloor is morphologically complex with several sub-basins, including three main sub-basins named West, East, and South Alboran Basins, ridges, and seamounts. The most prominent structure in the Alboran Sea is the Alboran Ridge which stretches southwest from the volcanic Alborán Island.

Oceanography

Surface currents in the Alboran Sea, influenced by the prevailing winds, flow eastward, bringing water from the Atlantic into the Mediterranean; deeper subsurface currents flow westward, carrying saltier Mediterranean water over the Gibraltar sill into the Atlantic. Thus there is typically a vertical rotary circulation, also known as a gyre, in the Alboran Sea as a result of this exchange of water.

Ecology

The Alboran Sea is a transition zone between ocean and sea, containing a mix of Mediterranean and Atlantic species. The Alboran Sea is habitat for the largest population of

bottlenose dolphin Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the comm ...

s and the last population of

harbour porpoise The harbour porpoise (''Phocoena phocoena'') is one of eight extant species of porpoise. It is one of the smallest species of cetacean. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar ...

s in the western Mediterranean, and is the most important feeding grounds for

loggerhead sea turtle The loggerhead sea turtle (''Caretta caretta'') is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around in carapace length when fully ...

s in Europe. The Alboran sea also hosts important

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

, including

sardine "Sardine" and "pilchard" are common names for various species of small, oily forage fish in the herring family Clupeidae. The term "sardine" was first used in English during the early 15th century, a folk etymology says it comes from the It ...

s and

swordfish Swordfish (''Xiphias gladius''), also known as broadbills in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordf ...

. In 2003, the

World Wildlife Fund The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the W ...

raised concerns about the widespread drift net fishing endangering populations of dolphins, turtles, as well as other marine animals. An arc of mountains, known as the Gibraltar Arc, wraps around the northern, western and southern sides of the Alboran Sea. The Gibraltar Arc is made up of the

Baetic Cordillera The Baetic System or Betic System ( es, Sistema Bético) is one of the main systems of mountain ranges in Spain. Located in the southern and eastern Iberian Peninsula, it is also known as the Cordilleras Béticas (Baetic Mountain Ranges) or B ...

of Southern Spain and the Rif Mountains of Morocco. These mountains, known to ecologists as the Baetic-Rifan complex, comprise one of the Mediterranean's

biodiversity hotspot A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation. Norman Myers wrote about the concept in two articles in ''The Environmentalist'' in 1988 and 1990, after which the c ...

s; like the Alboran Sea, the Baetic-Rifan complex represents a transition between the Mediterranean and Atlantic (

Macaronesia Macaronesia (Portuguese: ''Macaronésia,'' Spanish: ''Macaronesia'') is a collection of four volcanic archipelagos in the North Atlantic, off the coasts of Africa and Europe. Each archipelago is made up of a number of Atlantic oceanic islands ...

n) ecological zones. The moderating influence of the Atlantic has allowed many

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

species in the Baetic and Rif mountains to survive the climatic fluctuations of the last few million years that have caused them to become extinct elsewhere around the Mediterranean basin.

Islands

There are some small islands in the sea: * Isla de Alborán * Islas Chafarinas * Peñón de Alhucemas *

Peñón de Vélez de la Gomera (; ) is a Spanish exclave and rocky tied island, in the western Mediterranean Sea, connected to the Moroccan shore by a sandy isthmus. It is also connected to a smaller islet to the east, La Isleta, by a rocky isthmus. The tied island was name ...

References

Notes

Sources

* * * {{List of African seas Marginal seas of the Mediterranean Seas of Spain Bodies of water of Morocco Bodies of water of Algeria Morocco–Spain border Gibraltar–Spain border Algeria–Morocco border Seas of Africa Back-arc basins