he Mediterranean Sea connects to the vastness of the Atlantic through the smallest of natural channels: The Strait of Gibraltar is only about 8 miles wide. People have swum across the Strait, and it is easy to see from Spain to Morocco on a normal, clear day. It seems like it would not take much for nature to simply close that connection between Europe and Africa, and in so doing isolate the Mediterranean Sea. Indeed, this has happened before.
About six million years ago, something caused the Mediterranean to be cut off. Perhaps it was an ice age that decreased the sea level enough to leave a land bridge between Spain and Morocco. The Mediterranean’s isolation could also have been the outcome of tectonic processes.
