The Mediterranean Sea was once completely dry — about 5.6 million years ago, the connection to the Atlantic Ocean was closed by geological shifts, and the entire sea evaporated into a massive salt-floored basin two miles below sea level, which remained empty for roughly 600,000 years before the Strait of Gibraltar reopened and the Atlantic refilled it in what may have been the largest waterfall in Earth’s history

About 5.6 million years ago, the Mediterranean Sea began to evaporate. The Strait of Gibraltar, the narrow connection between the Mediterranean and the Atlantic Ocean, closed for the last time during a slow tectonic shift between Africa and Europe. The basin lost more water to evaporation each year than it gained from rivers and rainfall, [...] The post The Mediterranean Sea was once completely dry — about 5.6 million years ago, the connection to the Atlantic Ocean was closed by geological shift