His name is Paratetis (Paratethys) y It was the largest megalake that has ever existed on our planet. It contained more water than 10 times the volume of all modern lakes combined, covering at its best more than 2.8 million square kilometers; even slightly larger than the Mediterranean Sea itself (which is 2.5 million square kilometers in area). It was so colossal that it would have stretched from the eastern Alps to what is now Kazakhstan in central Asia.
What happened to the megalake?
The European continent during the late Miocene was quite different from how we know it today. The immense megalake or sea of Paratethys disappeared due to a “disaster” that wiped out most of its life forms less than 10 million years ago, according to a study published in the journal Scientific Reports which identifies up to four climate-driven cataclysmic cycles that shrank the lake and likely killed off significant numbers of the species that called it home. The water, a mass from which both the Caspian Sea, the Aral and the Black Sea come, receded in various phases until it almost disappeared.
The largest lake in the world
The lake would have contained tremendous aquatic life: from molluscs and crustaceans to small whales and dolphins that would have evolved to adapt to this “little” constrained environment. But few creatures survived as the lake dwindled, lost to evaporation and increased in salinity. The lake fragmented and the central basin, which is now the Black Sea, became particularly toxic and barren.
“It must have been a post-apocalyptic prehistoric world, an aquatic version of the wastelands of Mad Max”comments geologist Wout Krijgsman from the University of Utrecht in the Netherlands and co-author of the paper.
The researchers based their estimates on geological and fossil records within the Black Sea, where Paratethys originally existed. In addition to the Black Sea, the Caspian Sea, the Aral Sea, Lake Urmia, Lake Namak and many others, are also remains of the megalago Paratethys that formed about 12 million years ago, after a giant sea became disconnected from the ocean, and life evolved independently for 5 million years, isolated from the rest of the world.
megalakeDan Palcu; NaturalEarth
The study
To reach this conclusion, the experts studied fossil records, sedimentary deposits and the geology of the area around the Black Sea (the center of Paratethys) to identify four major drops in water level over several million years, while also making a modeling and simulation of water levels throughout the region. The most severe fall occurred between 7.65 million and 7.9 million years ago. During this episode (called Great Khersonian Drying), Paratethys water levels plummeted as much as 250 meters, separating the megalake into small lakes that would have been toxic to most aquatic life. According to the scientists’ calculations, the megalago could have lost up to 70% of its surface area and up to a third of its volume during these periods of great drought. Crises similar to the drying up of Lake Aral, but on a larger scale.
“Partial desiccations of megalakes coincide with climate, food web, and landscape changes in Eurasia, although the exact triggers and mechanisms remain to be resolved,” the authors write.
Referencia: Palcu, D.V., Patina, I.S., Șandric, I. et al. Late Miocene megalake regressions in Eurasia. Sci Rep 11, 11471 (2021). https://doi.org/10.1038/s41598-021-91001-z
