How does the submarine ridge near Sicily divide the Mediterranean Sea?

A submarine ridge located between the island of Sicily and the African coast serves as a natural boundary that divides the Mediterranean Sea into two distinct parts: the western and eastern basins.1

This ridge, which includes the Strait of Sicily, features a sill depth of approximately 1,200 feet (365 metres). Because the straits generally do not exceed 1,500 feet (460 metres) in depth, this submarine shelf effectively acts as a barrier between the two major regions of the sea.12