What is the deepest lake on Earth by maximum depth?

Lake Baikal is the deepest lake on Earth, reaching a maximum depth of 1,642 metres.

The ancient freshwater lake lies in southern Siberia, Russia. It formed in an active continental rift zone, where the Earth’s crust is pulling apart. That tectonic setting helps explain both its great depth and its exceptionally old geological history. Scientists estimate that Baikal is about 25 to 30 million years old.

Baikal contains roughly 20 percent of the world’s unfrozen surface freshwater, making it a major global freshwater reservoir. It is also famous for unusual biodiversity, including the endemic Baikal seal, the only seal species that lives exclusively in freshwater. The lake freezes during winter, creating a broad seasonal ice surface.

Lake Tanganyika is the second-deepest lake, while Lake Superior is the largest freshwater lake by surface area. Those distinctions are different from maximum depth. Baikal’s long, narrow shape and rift-basin geology make it a key natural laboratory for studying deep lakes, evolution, and continental tectonics.