Tectonic plate movements and falling sea levels once separated the Mediterranean Sea from the Atlantic Ocean, causing seawater to evaporate and create vast saline basins.
Previously, the Mediterranean Sea transformed into a giant salty basin about half a million years ago. Evidence of this geological disturbance still exists today and there is a possibility that the same disaster could happen again in the future, according to IFL Science. This event is called the Messinian salt crisis. According to researchers’ hypothesis, changes in sea level prevented the Atlantic Ocean from flowing into the Mediterranean Sea, pushing the sea into an almost completely dry period 5.33 – 5.97 million years ago.
Many scientists believe that the Messinian salt crisis occurred due to the discovery of a 1.5 km thick layer of salt along the Mediterranean seabed, first confirmed in the early 1970s. However, not all scientists believe The audience agrees on the nature or scale of the event.
One of the main reasons for the Messinian salinity crisis is likely to be tectonic plate movements. The African plate and the Eurasian plate slowly crashed into each other over thousands of years. Ultimately, their slow-motion collision led to the closure of the Strait of Gibraltar, a narrow body of water connecting the Atlantic Ocean and the Mediterranean Sea.
Another factor is that falling sea levels make it harder for ocean water to flow through the Strait of Gibraltar. A 2015 study linked the drop in global sea levels around this time to the expansion of the Antarctic ice shelf, trapping more of the world’s water around the South Pole and away from the North Pole. Western Ocean.
The Mediterranean is a sea that is easily affected by the above changes. Because it is located in a relatively warm and dry area of the planet, seawater evaporates at a very rapid rate. Without replenishment from the Atlantic Ocean, the closed sea dried up within just a few thousand years, leaving behind a salt-covered basin connecting parts of North Africa with southern Europe.
It was then theoretically possible to travel from present-day Morocco to Spain or from Libya to Italy. In fact, some animals migrate like this. Several Spanish islands such as Mallorca, Menorca, Ibiza, and Formentera were colonized by mainland animals during this dry period. At the same time, the crisis has devastated the Mediterranean’s marine biodiversity, killing 89% of endemic marine species.
After a long period of separation, tectonic activity caused the Gibraltar Strait to open again, creating conditions for a large amount of Atlantic water to rush into the Mediterranean Sea. Named the Zanclean flood, this was one of the most intense floods ever to occur on Earth.
Even today, the Mediterranean Sea remains saltier than the rest of the Atlantic Ocean partly due to geographical and climatic conditions that contributed to the Messinian salinity crisis. Although no longer separate from the Atlantic Ocean, the Mediterranean still has limited water exchange through the Strait of Gibraltar and is subject to high evaporation, leading to increased salinity.
Maybe a similar event will happen again in the future. The Earth’s tectonic plates are constantly shifting and the Mediterranean region is especially complex, demonstrating many unusual fault zones and tectonic debris overlapping each other. In a situation where the African plate continues to move toward the Eurasian plate, the two plates could merge to form the Eurasian supercontinent and erase the Mediterranean Sea from the map.