The Gem of Siberia

Lake Baikal is the deepest lake on Earth and is one of Asia’s largest bodies of fresh water. But, it seems to be getting bigger, faster than sediment supply can fill it. Russian scientists have taken a closer look at why.

For millions of years the chilling and crystal clear waters of Lake Baikal, the Gem of Siberia, have harboured a deep-water repository of unique and indigenous fauna, such as the Baikal seal, local forms of Arctic cisco and gobies, and a staggering one-fifth of the Earth’s fresh water. Alluvion constantly pours into the lake through landslides, mudflows and river flooding.

Lake Baikal

A Russian team has now shown that the volume of the incoming alluvion is four times less than the increase in size of the basin, which can only be explained by the changing crust of the Earth at the bottom of the lake and thankfully means that Baikal will still be on maps for years to come.

Boris Agafonov of the Institute of Earth’s Crust of the Siberian Branch of the Russian Academy of Sciences located in Irkutsk says that Lake Baikal is in a seismically active but comparatively young area. Geologically speaking, the elongated basin of the lake is a rift trough like those found at the bottom of the oceans.

Agafonov and his colleagues believe that the lake might be considered a prototype ocean. Satellite data have revealed that the Baikal basin is extending at a rate of 5 mm a year, which is equivalent to an increase in volume of about 20 million cubic metres but more than that Agafonov reckons the volume of the lake is also increasing as the original basin bed subsides through earthquake activity.

Agafonov’s calculations reveal that movements of the earth’s crust have resulted in the hollow of the lake having increased immensely since the massive earthquake of 1862. During the 139-year period, from 1862 to 2001, the volume of the lake increased by 3.95 billion cubic metres while the volume of water has increased by 2.9 billion cubic metres, Agafonov explained to Spotlight. The lake is, one would assume, likely to remain the Gem of Siberia for the foreseeable future.

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