Lake Baikal

Lake Baikal (Russian: озеро Байкал, tr. Ozero Baykal, IPA: [ozʲɪrə bɐjkal], Buryat: Байгал нуур, Mongolian: Байгал нуур, Baygal nuur, meaning "nature lake lake.is a rift in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast. 

Lake Baikal is a freshwater lake with the greatest volume in the world, containing roughly 20% of the world's unfrozen surface fresh water. and at 1,642 m (5,387 ft). It is also among the deepest .. clearest.of all the lakes, and thought to be the world's oldest lake [8] at 25 million years..It is the seventh-largest lake in the world by surface area. 

Like Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long crescent shape with a surface area of 31.722 km2 (12,248 sq mi). Baikal is home to more than 1,700 species of plants and animals, two-thirds of which can be found nowhere else in the world .. and was declared a UNESCO World Heritage Site in 1996 .. It is also home to Buryat tribes who reside on the eastern side of Lake Baikal,, rearing goats, camels, cattle, and sheep, where the regional mean .. Vary the average temperatures from a minimum of -19 ° C (-2 ° F) in winter to a maximum of 14 ° C (57 ° F) in summer .. However, as these are the mean temperatures, can be considerably colder winter nights and summer days can be considerably hotteren ..

Geography and hydrography..

Lake Baikal is in a rift valley, created by the Baikal Rift Zone, where the Earth's crust pulls apart... At 636 km (395 mi) long and 79 km (49 mi) wide, Lake Baikal has the largest surface area of any freshwater lake in Asia, at 31,722 km2 (12,248 sq mi), and is the deepest lake in the world at 1,642 m (5,387 ft). The bottom of the lake is 1,186.5 m (3,893 ft) below sea level, but below this lies some 7 km (4.3 mi) of sediment, placing the rift floor some 8–11 km (5.0–6.8 mi) below the surface: the deepest continental rift on Earth...In geological terms, the rift is young and active—it widens about two cm per year. The fault zone is also seismically active; there are hot springs in the area and notable earthquakes every few years. The lake is divided into three basins: North, Central, and South, with depths of about 900 m (3,000 ft), 1,600 m (5,200 ft), and 1,400 m (4,600 ft), respectively. Fault-controlled accommodation zones rising to depths of about 300 m (980 ft) separate the basins. The North and Central basins are separated by Academician Ridge while the area around the Selenga Delta and the Buguldeika Saddle separates the Central and South basins. The lake drains into the Angara tributary of the Yenisei. Notable landforms include Cape Ryty on Baikal's northwest coast.

Baikal's age is estimated at 25–30 million years, making it one of the most ancient lakes in geological history.[citation needed] It is unique among large, high-latitude lakes, in that its sediments have not been scoured by overriding continental ice sheets. U.S. and Russian studies of core sediment in the 1990s provide a detailed record of climatic variation over the past 250,000 years. Longer and deeper sediment cores are expected in the near future. Lake Baikal is furthermore the only confined freshwater lake in which direct and indirect evidence of gas hydrates exists...

The lake is completely surrounded by mountains. The Baikal Mountains on the north shore and the taiga are technically protected as a national park. It contains 27 islands; the largest, Olkhon, is 72 km (45 mi) long and is the third-largest lake-bound island in the world. The lake is fed by as many as 330 inflowing rivers.. The main ones draining directly into Baikal are the Selenga River, the Barguzin River, the Upper Angara River, the Turka River, the Sarma River, and the Snezhnaya River. It is drained through a single outlet, the Angara River.........

History....

The Baikal area has a long history of human habitation. An early known tribe in the area was the Kurykans, forefathers of two ethnic groups: the Buryats and Yakuts.

Lake Baikal was situated in the northern territory of the Xiongnu confederation, and was a site of the Han–Xiongnu War, where the armies of the Han dynasty pursued and defeated the Xiongnu forces from the second century BC to the first century AD. They recorded that the lake was a "huge sea" (hanhai) and designated it the North Sea (Běihǎi) of the semi mythical Four Seas... The Kurykans, a Siberian tribe who inhabited the area in the sixth century, gave it a name that translates to "much water". Later on, it was called "natural lake" (Baygal nuur) by the Buryats and "rich lake" (Bay göl) by the Yakuts.[38] Little was known to Europeans about the lake until Russia expanded into the area in the 17th century. The first Russian explorer to reach Lake Baikal was Kurbat Ivanov in 1643...'

Russian expansion into the Buryat area around Lake Baikal[40] in 1628–1658 was part of the Russian conquest of Siberia. It was done first by following the Angara River upstream from Yeniseysk (founded 1619) and later by moving south from the Lena River. Russians first heard of the Buryats in 1609 at Tomsk. According to folktales related a century after the fact, in 1623, Demid Pyanda, who may have been the first Russian to reach the Lena, crossed from the upper Lena to the Angara and arrived at Yeniseysk.[41] Vikhor Savin (1624) and Maksim Perfilyev (1626 and 1627–1628) explored Tungus country on the lower Angara. To the west, Krasnoyarsk on the upper Yenisei was founded in 1627. There were a number of ill-documented expeditions eastward from Krasnoyarsk. In 1628, Pyotr Beketov first encountered a group of Buryats and collected yasak from them at the future site of Bratsk. In 1629, Yakov Khripunov set off from Tomsk to find a rumored silver mine. His men soon began plundering both Russians and natives. They were joined by another band of rioters from Krasnoyarsk, but left the Buryat country when they ran short of food. This made it difficult for other Russians to enter the area. In 1631, Maksim Perfilyev built an ostrog at Bratsk. The pacification was moderately successful, but in 1634, Bratsk was destroyed and its garrison killed. In 1635, Bratsk was restored by a punitive expedition under Radukovskii. In 1638, it was besieged unsuccessfully.

In 1638, Perfilyev crossed from the Angara over the Ilim portage to the Lena River and went downstream as far as Olyokminsk. Returning, he sailed up the Vitim River into the area east of Lake Baikal (1640) where he heard reports of the Amur country. In 1641, Verkholensk was founded on the upper Lena. In 1643, Kurbat Ivanov went further up the Lena and became the first Russian to see Lake Baikal and Olkhon Island. Half his party under Skorokhodov remained on the lake, reached the Upper Angara at its northern tip and wintered on the Barguzin River on the northeast side. In 1644, Ivan Pokhabov went up the Angara to Baikal, becoming perhaps the first Russian to use this route which is difficult because of the rapids. He crossed the lake and explored the lower Selenge River. About 1647, he repeated the trip, obtained guides and visited a 'Tsetsen Khan' near Ulan Bator. In 1648, Ivan Galkin built an ostrog on the Barguzin River which became a center for eastward expansion. In 1652, Vasily Kolesnikov reported from Barguzin that one could reach the Amur country by following the Selenga, Uda, and Khilok Rivers to the future sites of Chita and Nerchinsk. In 1653, Pyotr Beketov took Kolesnikov's route to Lake Irgen west of Chita, and that winter his man Urasov founded Nerchinsk. Next spring, he tried to occupy Nerchensk, but was forced by his men to join Stephanov on the Amur. Nerchinsk was destroyed by the local Tungus, but restored in 1658.

The Trans-Siberian Railway was built between 1896 and 1902. Construction of the scenic railway around the southwestern end of Lake Baikal required 200 bridges and 33 tunnels. Until its completion, a train ferry transported railcars across the lake from Port Baikal to Mysovaya for a number of years. At times during winter freezes, the lake could be crossed on foot—though at risk of frostbite and deadly hypothermia from the cold wind moving unobstructed across flat expanses of ice. In the winter of 1920, the Great Siberian Ice March occurred, when the retreating White Russian Army crossed frozen Lake Baikal. The wind on the exposed lake was so cold, many people died, freezing in place until spring thaw. Beginning in 1956, the impounding of the Irkutsk Dam on the Angara River raised the level of the lake by 1.4 m (4.6 ft)..