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Lake Baikal of Russia | (Nature Diaries) | Analysis Zone

60. Lake Baikal of Russia | (Nature Diaries) | Analysis Zone Planet Earth & Lakes Although practically all of Earth’s human population lives on dry land, our surface is 71% covered by water. Of that water, almost all of it is in the oceans, with just 2.5% of it in the form of freshwater. The majority of our fresh water is either frozen or in the ground. Most of Earth’s fresh water is in glaciers, ice caps, and permafrost, and water and ice beneath the surface. Most of the rest is in the large reservoirs of liquid water on our land masses: Earth’s lakes. Ice Age & Lakes Earth’s lakes are the primary location where liquid, surface fresh water is held, but most of them were formed by the retreat of glaciers. The majority of Earth’s fresh water is frozen, in the forms of glaciers and ice caps, and this becomes much more severe during ice ages: where the polar caps grow large and extend down to equatorial latitudes. The Formation Not every lake has a river or stream to flow into it, and not every lake was formed as a result of glacial or interglacial cycles and transitions. When a divergent plate boundary begins to spread, a feature known as a rift valley can begin to form. Initially, two parallel cliffs form, but sediment and other material later fills it. Lake Baikal history At least 25 million years old, Lake Baikal is the oldest lake in the world. The lake and the surrounding mountains were formed by the Earth’s crust fracturing and moving. It was probably originally a riverbed, but tremors and fractures in the Earth’s crust increased the size and widened the space between the shores. Melting glaciers also increased the water levels. Lake Baikal is in a rift valley and up to 2,000 earthquake tremors are detected each year. The earthquakes deepen the lake and increase its size continuously. Lake Baikal location Lake Baikal is located in south-central Russia near the Mongolian border. Lake Baikal has historically played a large role in the Russian imagination. It represents the unspoiled beauty of Russia and is sometimes referred to as the Sacred Sea. Lake Baikal plays a central part in many local creation myths and appears throughout Russian folklore. Though it is in southern Siberia, the lands around Lake Baikal are generally warmer than the rest of the area because large bodies of water have a moderating force. Lake Baikal Dimensions Lake Baikal is the 7th largest lake in the world by surface area, but holds more fresh water than any other lake by quite a wide margin. Found in southern Siberia, it has little over 31,000 square kilometres or 12,000 square miles of surface area. However, the regions on either side of Lake Baikal are at an extremely high altitudes, with many locations exceeding 2000 meters or nearly 7,000 feet in elevation. Lake Baikal Weather The earth under Lake Baikal is heated. The cause of the heat is unknown. Lake Baikal is considered one of the clearest lakes in the world. During the summer, when the lake is full of melted ice from the Siberian mountains, it is sometimes possible to see more than 130 feet or 39 meter down. The stunning clarity is the result of the melted ice’s purity, plankton that eat floating debris and a lack of mineral salts in the lake. The average air temperature in winter is minus -21o C. How unique is Lake Baikal? The bottom of the lake is more than a full kilometer below sea level, but the rift valley that created it goes far deeper. According to research, there are approximately an additional 7,000 meters or 23,000 feet of sediment that have fallen into the rift valley over time, placing the rift floor an incredible 8 to 11 kilometers beneath the surface. This makes the geological rift that’s home to Lake Baikal, is the deepest continental rift on planet Earth. Lake Baikal Ecosystem The age, isolation and deep oxygenated water of Lake Baikal have resulted in one of the world’s richest freshwater ecosystems. About 80 percent of more than 3,700 species found at Lake Baikal are endemic, meaning they are found nowhere else on Earth. Probably the most famous of these species is the nerpa, the world’s only exclusively freshwater seal. Other endemic species include the oily, scale less golomyanka fish and the omul, a white fish that is one of Lake Baikal’s most famous dishes. Other land-based species around Lake Baikal include bears, reindeer, elk, wild boar, Siberian roe deer, polecats, ermine, sable and wolves. Earth Evolution Yet perhaps what’s most remarkable about Lake Baikal is the view it gives us into how Earth evolves with time. The geological processes at work here are the same ones that causes the ancient supercontinent of Pangaea to break up, and resulted in the formations of Earth’s oceans. Perhaps, hundreds of millions of years from now, the rift valley that is now home to Lake Baikal will become a saline body connected to our oceans. It is, by many measures, the greatest lake on our entire planet.