Scientists have long sought to understand an unusual climactic and geological event known as the Messinian Salinity Crisis. During this ecological catastrophe, which occurred around 5.97 to 5.33 million years ago, a huge amount of the Mediterranean Sea was dramatically transformed into a vast, salty lake. The level of the sea plunged, and a large basin of salty water was created. The giant deposits of the salts gypsum and halite affected the geology of the region and the salt levels of oceans around the world. At least one million cubic kilometers of salt built up in the Mediterranean during this short period.
Now, scientists may know why this happened. The findings have been reported in Nature Communications.
In this report, scientists suggest that there was a first phase of the Messinian Salinity Crisis, which lasted around 35,000 years. During this time, salt accumulated in the eastern part of the Mediterranean Sea, which started because water flowing out of the sea towards the Atlantic Ocean was blocked.
The second phase began as the buildup of salt became more widespread across the whole the Mediterranean Sea. There was a rapid loss of water from evaporation, which happened in under 10,000 years, and the level of the Mediterranean dropped about 1.7 to 2.1 kilometers in the eastern part of the Mediterranean, and about 0.85 km in the western Mediterranean. About seventy percent of the Mediterranean Basin was lost during this time.
There were huge consequences for the local animals and plants, as well as for the entire landscape of the Mediterranean. Some volcanic eruptions occurred, as the crust of the Earth lifted up from the lost weight of the evaporated water, and climactic events were triggered around the globe.
Sources: CNRS, Nature Communications