Lake Baikal

Podcast Transcript

It is the deepest lake in the world, the oldest lake in the world, and it holds more freshwater than all five of the Great Lakes combined.

Hidden in Siberia, Lake Baikal is a place where geology, evolution, history, and myth all come together.

It has its own seal species, its own unique ecosystem, and a story that stretches back millions of years.

Learn more about Lake Baikal, one of the greatest natural wonders on Earth, on this episode of Everything Everywhere Daily.

Lake Baikal holds a set of distinctions that are unmatched by any other body of freshwater on Earth. It is simultaneously the world’s oldest lake, its deepest, and, by volume, the world’s largest reservoir of unfrozen freshwater.

Lake Baikal lies in southeastern Siberia, in Russia, north of Mongolia and near the city of Irkutsk. It is long, narrow, and crescent-shaped, stretching roughly northeast to southwest. It is about 640 kilometers (400 miles) long but only a few dozen kilometers wide in many places.

The lake is surrounded by mountains, including the Baikal Mountains to the northwest and the Barguzin Range to the east. These ranges give Baikal its dramatic appearance: steep shorelines, deep blue water, and rocky capes extending into the lake.

One interesting fact about the lake is that it has hundreds of inflowing rivers and streams, but only one going out: the Angara River, which flows west from the lake toward the city of Irkutsk and eventually joins the Yenisei River system on its way to the Arctic Ocean.

That fact alone makes Baikal hydrologically important, as it is not just a scenic body of water; it is a major node in the freshwater system for all of northern Asia.

In winter, Baikal freezes over, often forming exceptionally clear ice. In summer, its vast mass of water keeps the surrounding shores cooler than inland areas. The lake’s seasonal ice cover is not just picturesque; it is central to its ecology, affecting light, algae, oxygen, circulation, and the timing of life cycles in the water.

Lake Baikal exists because Asia is slowly tearing itself apart at that location. It lies within the Baikal Rift Zone, one of the world’s most important active continental rift systems.

In most lakes, time works against them becoming deeper. Sediment fills basins, rivers, and streams, reducing water levels, and lakes eventually shrink or disappear.

Baikal has survived because tectonic forces keep deepening and renewing its basin. The rift began forming tens of millions of years ago when the crust stretched apart, creating a long trough. Water filled the depression, rivers carried sediment into it, and the lake evolved into the enormous basin we see today.

Seismic studies show that Baikal contains several miles of sediment at the bottom of the lake, which accumulated over millions of years. Researchers have identified deposits roughly 2 to 4.5 miles thick.

Because of the rift, Baikal is less an ordinary lake and more an embryonic ocean basin, though it is not certain it will ever become one. Its formation is very similar to the creation of African rift lakes, which I covered in a previous episode.

The rift is still active. Earthquakes occur in the region, hot springs are found around the lake, and the surrounding landscape continues to be shaped by faulting and uplift.

What really sets Lake Baikal apart from every other lake in the world is its volume and depth, which are both a result of the rift.

The lake reaches a maximum depth of roughly 1,642 meters (about 5,387 feet), making it the deepest lake in the world by a wide margin. The depth of the lake doesn’t include the miles of sediment that extend beyond its bottom.

Because it holds roughly 23,600 cubic kilometers of water, Baikal contains approximately 20 percent of all the unfrozen freshwater on Earth’s surface, more than all five of North America’s Great Lakes combined, despite having a surface area smaller than Lake Michigan.

Baikal’s depth also gives it unusual circulation patterns. Deep lakes can become stratified, with upper and lower waters mixing only under certain conditions. Yet Baikal’s waters are oxygenated to remarkable depths compared with many other deep lakes. This supports life far below the surface and helps explain the lake’s unusual biological richness.

Baikal is sometimes called the “Galapagos of Russia” because of its age, isolation, and endemic species.

A large share of Baikal’s plants and animals is found nowhere else on Earth. Its most famous animal is the Baikal seal, or nerpa, the only exclusively freshwater seal species in the world.

How seals reached Baikal remains debated, but the most likely explanation involves ancient connections through Arctic river systems, followed by isolation and adaptation.

The lake is also home to the omul, a whitefish that has historically been central to local diets and commerce. Its invertebrate life is even more remarkable. Baikal has an extraordinary diversity of amphipods, sponges, mollusks, worms, and microscopic organisms.

Many are highly specialized, adapted to cold, clear, oxygen-rich water and to ecological niches that do not exist in younger, shallower lakes.

The lake’s biodiversity is not just a catalog of strange species. It is a living experiment in evolution. Because Baikal is so old, lineages have had time to diversify inside the lake itself.

Human presence around Baikal reaches back many thousands of years, with archaeological evidence of hunter-gatherer populations along its shores extending into the Upper Paleolithic. Over subsequent millennia, the region became home to various Turkic, Mongolic, and Tungusic-speaking peoples.

By the time of Russian eastward expansion in the seventeenth century, the dominant indigenous group in the region was the Buryats, a Mongolic people who developed a rich shamanistic and, later, Tibetan Buddhist-influenced religious tradition in which Baikal itself occupied a sacred place.

Russian Cossack explorers reached the lake in the 1640s as part of the broader Russian conquest and colonization of Siberia, and Baikal was gradually incorporated into the expanding Russian Empire over the following decades.

Its remoteness made it a natural site for sending people into exile. From the eighteenth through the nineteenth and into the twentieth centuries, the Siberian regions surrounding Baikal became a destination for political prisoners and exiles, including Decembrists after the failed 1825 uprising and numerous later revolutionaries, giving the lake and its surrounding taiga an association with punishment and isolation in the Russian cultural imagination.

Scientific investigation of the lake accelerated in the nineteenth century, particularly under the auspices of the Russian Academy of Sciences and later Soviet scientific institutions, culminating in the establishment of dedicated special Lake Baikal research bodies in the twentieth century.

Lake Baikal played a major role in one of the largest infrastructure projects in world history: the Trans-Siberian Railway. In the late 19th century, Russia sought to connect European Russia with the Pacific.

The railway was meant to supply, populate, and integrate Siberia, while moving raw materials and strengthening imperial control across the continent. The Trans-Siberian, as part of a wider 19th-century Russian rail expansion, was intended to supply and populate Siberia and deliver raw materials westward

Baikal posed a major engineering problem. The railway could reach the lake’s western and eastern shores, but the lake itself interrupted the line. Before the Circum-Baikal Railway was completed, trains and passengers had to cross the lake by ferry. In the winter, icebreakers ferried train cars across the lake to connect the two railroads.

The Circum-Baikal Railway, built around the southern end of the lake in the early 20th century, was an extraordinary engineering achievement. It required tunnels, bridges, and retaining walls along steep rocky shorelines. It was the most technically difficult and expensive sections of the Trans-Siberian route.

Later, the construction of the Irkutsk hydroelectric station on the Angara River changed the railway’s role. Water levels rose, older sections were affected, and the main Trans-Siberian route was redirected. The Circum-Baikal line was eventually reduced to a dead-end historic and tourist route rather than a main artery.

During the Soviet period, Baikal became an industrial site and, subsequently, one of the earliest and most prominent environmental controversies in Soviet history.

Established in 1966 on the lake’s southern shore, the Baikalsk Pulp and Paper Mill was built to manufacture a specific grade of cellulose initially intended for aircraft tire cord. Its construction triggered sustained protests from Soviet scientists and authors, which was remarkable as there was almost no dissent inside the USSR.

Facing various economic and political pressures, the mill functioned intermittently until it was permanently closed in 2013. Nevertheless, the toxic accumulation within its legacy waste lagoons continues to be an active concern.

Since the collapse of the Soviet Union, the largest economic activity in the region has been tourism. Baikal is one of Russia’s most famous natural destinations, drawing visitors to the shore of the lake, Olkhon Island, the Circum-Baikal Railway, winter ice routes, hiking trails, and lake cruises.

The region has attracted hotel investment and was declared a special economic zone in 2007, partly to encourage tourism development. Tourism creates many jobs, but it also creates pressure from sewage, waste, illegal construction, and poorly regulated operators. Recent studies have warned that mass tourism around Baikal can damage the very environment that makes the lake economically valuable.

Fishing is another traditional economic use, especially the catch of omul, the lake’s famous whitefish. Fishing has cultural and commercial importance for lakeside communities, but it is no longer the dominant industry. In economic terms, Baikal’s fishery is less important because of its scale than because it is a local food source.

Perhaps the most important proposal floated for the lake’s future concerns its vast freshwater reserves.

The most realistic proposals have involved bottling Baikal water and selling it, especially to China. This is not a fantasy. Several companies have tried to market Baikal water as a premium natural product, and the idea has obvious commercial appeal: “pure Siberian water from the world’s deepest lake” is a powerful brand.

The most controversial example came in 2019, when a Chinese-funded bottling plant near the village of Kultuk on the southern shore of Baikal became the focus of public outrage.

A more dramatic idea is a pipeline from Baikal to northern or northwestern China. China has chronic water problems, especially in the north and northwest, where agriculture, industry, cities, and desertification all put pressure on limited supplies.

One of the most widely reported proposals appeared around 2017, when planners in Lanzhou, China, floated the idea of pumping water from Lake Baikal to relieve shortages. Reports described possible routes of 1,000 to 2,000 kilometers, with water being pumped uphill and across extremely difficult terrain.

The odds of this ever happening are very, very low for obvious geopolitical and engineering reasons. Russia will probably never allow water to be pumped out of the lake, regardless of how much water it holds.

Moreover, lowering the lake’s water level would endanger many endemic species in and around the lake, and the lake was listed as a UNESCO World Heritage Site in 1996, which gives it a protected status.

Over the next several million years, Lake Baikal will probably become larger and deeper as the rift continues to widen and Asia continues to spread apart.

Lake Baikal is far more than just a large body of freshwater. It is one of the planet’s oldest geological stories, a living laboratory of evolution, a sacred landscape for native people, and a resource whose value only increases as freshwater becomes more precious.

Despite its massive size, its location and age make it extremely fragile. Which sort of proves that even big things can be extremely sensitive.