Just like mountains, lakes on Earth can boast incredible ages, with some being over a million years old. In fact, there are only about 20 ancient lakes on our planet, but the title of the oldest lake is undisputed.
Earth’s oldest lake is Lake Baikal, located in southeast Siberia, Russia. Scientists estimate this vast freshwater lake to be approximately 25 million years old, making it not only the oldest but also a vital ecological treasure. Ted Ozersky, an associate professor of biological limnology at the University of Minnesota, emphasizes the significance of Lake Baikal’s age in understanding the evolution of freshwater ecosystems. In comparison, the renowned Great Lakes of North America were formed much more recently, less than 20,000 years ago, during the last glacial period.
Following closely behind, the second oldest lake is Lake Issyk-Kul in Kyrgyzstan, which formed around 20 million years ago. This lake, despite being similarly ancient, does not match Baikal in terms of depth or biodiversity.
Lake Baikal spans an impressive area of 12,239 square miles (31,700 square kilometers), ranking it as the seventh-largest lake in the world. Beyond its age, it is also recognized as the deepest lake globally, plunging to about 1 mile (1.6 kilometers) at its deepest point.
However, the depth measurement only accounts for the water; the actual geological basin is even more profound, with depths ranging from 3.1 to 4.3 miles (5 to 7 kilometers) of sediment layer at the bottom. To understand the sediment accumulation over millions of years, researchers utilize seismic surveys, which allow them to estimate how quickly sediment has formed in this ancient lake.
Ozersky notes that these techniques are crucial for unraveling the lake’s geological history and its role in the Earth’s ecosystem.
Lake Baikal is not just a remarkable geographical feature; it is also a biodiversity hotspot, home to thousands of plant and animal species, many of which are found nowhere else on Earth. Its unique characteristics and the insights it provides into the planet’s past make Lake Baikal a subject of ongoing research and fascination for scientists worldwide.
