from the rest at about 100 m depth. These waters flow out and down the continental slope, losing salinity, until they begin to mix and equilibrate more rapidly, much farther out at a depth of about 1000 m. The Mediterranean outflow water layer can be traced for thousands of kilometres west of the Strait, before completely losing its identity.

During the Second World War, German U-boats used the currents to pass into the Mediterranean Sea without detection, by maintaining