Photo: Dr. Jean-Paul Rodrigue, 2013.
The dividing line between Europe and Asia, the link-up between the Mediterranean (Marmara Sea) and the Back Sea, the Bosporus is an ancient valley along a fractured tectonic line. The strait is entirely within Turkey and divides Istanbul in two. It is considered an international shipping lane of free access, but Turkey reserves the rights to close its navigation to other nations. Since the independence of Ukraine in 1991, the strait of Bosporus retook strategic importance for international trade with the adjacent countries in the Black Sea, such as Ukraine and Georgia. This trade notably involves grain and oil. The strait is also intensively used for ferries across Istanbul, a city of more than 13 million people. Three suspension bridges (Bosporus, Fatih Sultan Mehmet, and Yavuz Sultan Selim) crosses the Bosporus, the latest completed in 2016. Since the capacity of the Bosporus is limited and that navigation can be hazardous, there are projects about digging a canal across the peninsula.