The Mediterranean Sea nearly evaporated completely approximately 5.5 million years ago during a period known as the Messinian salinity crisis. This geological event left behind massive deposits of salt, some reaching thicknesses of 3 kilometres, which researchers call salt giants.
A reduction in water flow from the Atlantic Ocean into the Mediterranean caused this crisis. Emmanuel Guillerm at the GFZ Helmholtz Centre for Geosciences in Potsdam, Germany, says current models fail to account for how salinity prevents water from evaporating.
Since 1979, the Dead Sea has seen its water level drop by 40 metres while its temperature rose by 3°C. The bottom of the Dead Sea has accumulated between 3 billion and 4 billion tonnes of salt over the same period.
Guillerm claims that isolating the Mediterranean from the ocean would trigger a 20°C temperature increase and a drawdown of several kilometres within a few thousand years. Wout Krijgsman at Utrecht University in the Netherlands said, "It is an interesting idea, and probably very relevant for understanding the water level in the Dead Sea."
The next step is therefore to reconstruct the evolution of water temperature in the Mediterranean Sea during the Messinian salinity crisis, Guillerm said.
