The Camarinal Sill is the sill separating 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 the ...

and 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 ...

. This threshold is the shallowest seafloor pass 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

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 ...

. It is located approximately 25 km west of the narrowest section of the Strait of Gibraltar and 20 km east of the Espartel Sill, at , at an elevation of −280 m.Science Direct. The boiling-water phenomena at Camarinal Sill, the strait of Gibraltar. Bruno, Juan-Alonso, Cózarb, et al
/ref>Morphology and structure of the Camarinal Sill from high-resolution bathymetry: Evidence of fault zones in the Gibraltar Strait
/ref> Its formation is linked to the Zanclean flood and the termination of the

Messinian salinity crisis The Messinian salinity crisis (MSC), also referred to as the Messinian event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partial or nearly complete desiccation (d ...

, when the Mediterranean was abruptly refilled through the Strait of Gibraltar, excavating the 900-metre-deep gorge that lies underneath the water. A competing hypothesis suggests that both the gorge and the Camarinal Sill are the result of fluvial erosion during the desiccation of the Mediterranean (Messinian salinity crisis). Marine waters must climb to that depth when flowing between both ocean domains. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

, submarines used the upper inflow current and the lower outflow current to go in and out of the Mediterranean Sea without using their engines, to avoid being noticed from the surface.Paterson, Lawrence. ''U-Boats in the Mediterranean 1941–1944''. Chatham Publishing, 2007, pp. 19 and 182.

References

{{reflist Strait of Gibraltar Messinian Aquatic sills