If you stood on the edge of this lake and dropped a stone, it would fall deeper than the Grand Canyon. But that’s not even the strangest part. Beneath the frozen surface of Lake Baikal in Siberia lies a watery world so old and vast, it contains nearly a quarter of Earth’s unfrozen freshwater. And it’s still growing. With shifting land beneath and ancient creatures swimming in its depths, Baikal doesn’t just break records — it rewrites what we think a lake can be.
A Crack in the Earth That Became a Giant
Lake Baikal didn’t come from a glacier like most deep lakes. It was born from the Earth pulling itself apart. Millions of years ago, the ground in southern Siberia split open in a violent rift, creating a deep scar that would fill with water over time. Today, that rift is still moving. Scientists say the Eurasian and Amur tectonic plates continue to drift apart by around 4 millimetres each year. As a result, Baikal isn’t just deep — it’s getting deeper.
At its lowest point, the lake plunges down 1,642 metres, deeper than any other lake in the world. That’s enough to fit 13 stacked Sydney Towers underwater. And below the water’s bottom lies more than 7 kilometres of ancient sediment, making the basin even more massive than it seems.
The Lake That Outsizes Nations
Lake Baikal stretches over 636 kilometres long and up to 79 kilometres wide. It holds about 23,600 cubic kilometres of water — more than the five Great Lakes of North America combined. That’s around 20 percent of the world’s unfrozen freshwater.
In winter, the lake freezes over with a sheet of ice so thick and clear, people can walk or even drive across it. Some say it looks like glass. The ice often cracks, making thunder-like noises that echo across the lake. Even NASA satellites have captured these icy patterns from space.
But underneath this beauty is something far more mysterious: Baikal’s waters are home to creatures found nowhere else on Earth.
Life That Glows and Creeps in the Cold
Over 80 percent of Baikal’s 3,700 known species exist only in this lake. Among them is the Baikal seal, or nerpa, the only freshwater seal in the world. It lives happily in the lake’s frigid waters and gives birth on the ice.
There are also strange fish like the golomyanka, a translucent, scale-free swimmer that gives birth to live young and can survive crushing pressures in the deep. Some deepwater organisms even glow in the dark. Scientists believe some of these species evolved in total isolation over millions of years, adapting to cold, darkness and extreme pressure.
Because of this, Lake Baikal is often called the “Galápagos of Russia.”
A Lake That Watches the Past
Baikal is more than just a water body. It’s a natural time capsule. The lake’s untouched sediment layers stretch back millions of years, holding ancient clues about Earth’s climate. Scientists study these layers to learn how the planet’s temperature and weather patterns have changed over time. They even found remains of plants and animals that no longer exist.
What’s more, Lake Baikal is one of the cleanest large lakes on the planet. Its clarity comes from tiny organisms that filter the water and help keep it pure. In some areas, you can see 40 metres straight down.
Quakes, Telescopes and a Growing Mystery
Because the lake sits on active fault lines, earthquakes often shake the region. While most are small, they remind people that the ground beneath Baikal is very much alive.
Scientists are also using the lake for cutting-edge experiments. Deep beneath the surface, in one of its darker corners, sits the Baikal-GVD neutrino telescope. This massive underwater instrument is helping researchers look for tiny particles from space called neutrinos — and maybe even find the answers to cosmic mysteries.
