Mediterranean Sea

The Mediterranean Sea (35 degrees north, 18 degrees east) is a sea of the Atlantic Ocean almost completely enclosed by land: on the north by Europe, on the south by Africa, and on the east by Asia. It covers an approximate area of 2.5 million kmІ (965,000 miІ), but its connection to the Atlantic (the Strait of Gibraltar) is only 14 km (9 mi) wide. In oceanography, it is sometimes called the Eurafrican Mediterranean Sea of the European Mediterranean Sea, to distinguish it from Mediterranean seas elsewhere.

The Mediterranean was once thought to be the remnant of the Tethys Ocean. It is now known to be a structurally younger ocean basin know as Neotethys. Neotethys formed during the Late Triassic and Early Jurassic rifting of the African and Eurasian plates.

Being nearly landlocked affects the Mediterranean Sea's properties; for instance, tides are very limited as a result of the narrow connection with the Atlantic Ocean. The Mediterranean is characterized and immediately recognized by its imposing deep blue color, especially around the Greek islands.

Evaporation greatly exceeds precipitation and river runoff in the Mediterranean, a fact that is central to the water circulation within the basin. Evaporation is especially high in its eastern half, causing the water level to decrease and salinity to increase eastward. This pressure gradient pushes relatively cool, low-salinity water from the Atlantic across the basin; it warms and becomes saltier as it travels east, then sinks in the region of the Levant and circulates westward, to spill over the Strait of Gibraltar. Thus, seawater flow is eastward in the Strait's surface waters, and westward below; once in the open ocean, this chemically-distinct "Mediterranean Intermediate Water" can persist thousands of kilometers away from its source.

The geology of the Mediterranean is complex, involving the break-up and then collision of the African and Eurasian plates, and the Messinian Salinity Crisis in the late Miocene when the Mediterranean dried up.

As a result of the drying of the sea during the Messinian Salinity Crisis, the marine biota of the Mediterranean are derived primarily from the Atlantic Ocean. The North Atlantic is considerably colder and more nutrient-rich than the Mediterranean, and the marine life of the Mediterranean has had to adapt to its differing conditions in the five million years since the basin was reflooded. The opening of Suez Canal in 1869 created the first salt-water passage between the Mediterranean and Red sea. The Red Sea is higher than the Eastern Mediterranean, so the canal serves as a tidal strait that pours Red Sea water into the Mediterranean. The Bitter Lakes, which are hyper saline natural lakes that form part