Bosporus and Dardanelles (IMAGE) University of Kansas Caption The sea level in the Bosporus and Dardanelles at the Last Glacial Maximum (20,000 years ago) versus today. Note that 20,000 years ago one-third of the route from the Black Sea to the Aegean Sea was occupied by a deep lake, which would have interrupted the portage and might have encouraged human settlement at each of its ends. Credit Dobson, et al. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.