The Mediterranean dries up
Cut off from the Atlantic, an entire sea evaporates, leaving salt flats two kilometres below sea level.
- When
- —
- Duration
- 627 thousand years
- Known to
- ± 50 thousand years
- Era
- Miocene, Cenozoic
Tectonic uplift closes the corridors between the Atlantic and the Mediterranean, and because the basin loses far more water to evaporation than its rivers supply, it desiccates. Between 5.96 and 5.33 million years ago a salt layer up to two kilometres thick accumulates across the basin floor — an estimated 6 per cent of all the salt dissolved in the world's oceans, enough that removing it measurably lowered global ocean salinity. Rivers cut deep canyons down to the exposed floor; the Nile's is buried beneath Cairo. The evidence was found by deep-sea drilling in 1970 and startled everyone.