Messinian Salinity Crisis

About 5.6 million years ago, the Mediterranean Sea was cut off from the Atlantic Ocean, likely due to tectonic shifts that closed the Strait of Gibraltar. For thousands of years afterward, the Mediterranean evaporated away, becoming saltier and leaving massive deposits of salt and minerals on the sea bed until the sea had disappeared. The straight was reopened and the sea refilled during a massive flood 500,000 years later. Today, the sea is still saltier than the Atlantic Ocean. Why? More...