Research from USP on the world’s largest lake enters the “Guinness,” the record book
The team discovered the immense proportions of the magnificent Paratethys, the largest lake ever to exist on Earth, with the Caspian, Black, and Aral Seas as modern remnants.
The record is the result of the work of researchers from the Oceanographic Institute of USP and universities in Europe. In the photo, the cliffs of Bolata Bay (Bulgaria) overlook the lake area. Photo by Dan Valentin Palcu.
The discovery of the dimensions of the Paratethys megalake has just entered the Guinness Book of Records, officially becoming the largest lake of all time thanks to the latest research from the Oceanographic Institute (IO) of USP and the effort of its researchers. Using the technique called magnetostratigraphy – which applies the record of Earth’s magnetic field polarity reversals in rocks as a dating tool – and digitized paleogeographic reconstructions to determine the size and volume of Paratethys, the research became essential for this fascinating story led by researcher Dan Valentin Palcu.
“For a long time, it was believed that there was a prehistoric sea there, known as the Sarmatian Sea, but now we have clear evidence that for about 5 million years this sea became a lake – isolated from the ocean and filled with animals never seen elsewhere around the globe,” Palcu concludes.
The Paratethys megalake was characterized by a unique endemic fauna, including Cetotherium riabinini – the smallest whale ever found. Palcu and his colleagues also revealed the tumultuous history of Paratethys, marked by multiple hydrological crises and periods of drought. During the most severe crisis, the megalake lost more than two-thirds of its surface area and a third of its volume, with the water level dropping up to 250 meters. This had a devastating impact on the fauna, and many species became extinct.
The rocks formed during the megalake crises became cliffs on the coast of the Black Sea, where its geological history remained preserved. Photo by Dan Valentin Palcu.
Palcu emphasizes the profound significance of his research: “Our investigations go beyond mere curiosity. They reveal an ecosystem that responds extremely acutely to climate fluctuations. By exploring the cataclysms that this ancient megalake underwent as a result of climate change, we obtain valuable information that can elucidate potential ecological crises triggered by the climate changes our planet is currently undergoing, especially insights into the stability of toxic water basins like the Black Sea.”
He explains that the modern Black Sea reflects many environmental characteristics of its ancient counterpart, the Paratethys. Largely devoid of oxygen that sustains life, the depths of the Black Sea have waters rich in hydrogen sulfide, a toxic gas harmful to both humans and most animal species. Furthermore, Black Sea sediments contain “frozen” methane, an exceptionally potent greenhouse gas that could be released into the atmosphere in response to global warming, thus triggering various environmental catastrophes.
The megalake lost most of its surface, and the remaining water was divided between a central salt lake in the Black Sea basin (marked in red) and peripheral basins that periodically replenished and became cooler (light blue). Image: Scientific Reports.
Palcu, who is currently investigating the resilience of these ecologically fragile regions to climate change and human-induced modifications, emphasizes that deciphering the history of Paratethys is not just a journey into a tragic past but also a beacon of hope for the future.
“The Black Sea has the potential to become one of the largest natural carbon storage regions on Earth. Its stability is of paramount importance to unlock its capacity for future carbon storage initiatives and to prevent future ecological disasters.”
Earning a prominent place in the Guinness World Records is a significant achievement that breaks down the barriers between science and the general public. Since its inception in 1954, the publication has sold over 150 million books in more than 100 countries and has been translated into over 40 languages.
The study was a collaboration between USP (Brazil), Utrecht University (Netherlands), the Russian Academy of Sciences (Russia), the Senckenberg Biodiversity and Climate Research Center (Germany), and the University of Bucharest (Romania), funded by Fapesp.
*With information from the researchers.
The region where the Paratethys megalake was located according to the researchers. Image: Dan Valentin Palcu.