Earth’s deepest lake holds more fresh water than any other
Lake Baikal plunges to 1,642 metres in southern Siberia, making it the world’s deepest lake and—by volume—the largest body of fresh water on Earth. Its 31,722 square kilometres of surface rank only seventh globally, yet the rift’s depth changes the math.
Stretching 636 by 79 kilometres between Irkutsk Oblast and Buryatia, the Baikal Rift pulls apart about four millimetres a year, feeding hot springs and frequent quakes across North, Central, and South basins. Age estimates of 25–30 million years crown it geology’s oldest large lake, with sediments never stripped by continental ice. Gas hydrates appear here uniquely among confined freshwater lakes.
Clarity in winter open water can reach 30–40 metres; summer readings usually fall to 5–8 metres. Ice seals the surface for four to five months from early January into May or June. When the ice breaks, mixing leaves the top 300 metres at a uniform 4 °C in May and June, and the same even layer returns in October and November as the surface cools. Steady winds sweep the rift valley, and summer and autumn storms can raise waves of up to 4.5 metres.
More than a thousand plant and 2,500 animal species are logged, many endemic, including the nerpa seal. Underwater plants are scarce outside a few shallow bays, though more than 85 submerged species have been found, and the marsh thistle reaches the eastern edge of its range in the watershed. Olkhon, seventy-two kilometres long, leads twenty-seven islands beneath the Baikal, Barguzin, and Primorsky ranges. A national park protects those mountains and their taiga.
On the eastern side in Buryatia, Buryat communities keep goats, camels, cattle, sheep and horses through winters averaging around −19 °C and summers near 14 °C. Surface temperatures have risen almost 1.5 °C over fifty years, shortening ice seasons.
Source: Lake Baikal
