Exercise 2: The topography of the ocean floor.

This map shows the topography of what is known as the Mediterranean Sea. (Note that the colour coding of the depth contours differs from the previous maps.) Several deep basins can be seen. Connection with the remainder of the world ocean is through the Strait of Gibraltar.

The Black Sea is really a mediterranean sea of its own, connected with the Levantine Basin through the Bosporus and Dardanelles. In contrast to the main Mediterranean Sea, the Black Sea has a freshwater surplus, so its water is fresher than the water in the Levantine Basin.

As a complete system, the European-African Mediterranean Sea (including the Black Sea) has a freshwater deficit, and its water can be followed as a salinity maximum across the entire Atlantic Ocean.