Lake Baikal to become a new ocean - but not for 20 million years, say scientists

Crescent-shaped Lake Baikal is now the planet's deepest and oldest lake, emerging 25 million years ago on a tectonic crack, an area of 31,722 square kilometres  - larger in area than Belgium - containing 23 billion tons of water, or 20% of the world's unfrozen freshwater reserves. 

Geologist Dr Sergey Krivonogov has coordinated a major new study on the region and concluded that Baikal is an embryonic ocean.

The shores of the lake are reported to be moving apart at some 2 millimetres a year, while the surrounding mountains are rising at 5 to 6 mm annually, distinctly zippy in geological terms.

Depressions in this earthquake zones are deepening by a rapid 4 mm a year. 

An article in journal Gondwana Research reported: 'There is a huge rift in the Earth's crust, right in the centre of Eurasia, called the Baikal Rift Zone. 

'This crack is widening bit by bit, and unless the geodynamic conditions change, the biggest continent will again split in two 20 million years from now, and a new ocean will appear where Baikal is now.'

'Surprisingly, in the modern terrain we register very active movements that are happening as a part of the newest tectonic movements that began some 200,000 years ago,' said the scientist from the Sobolev Geology and Mineralogy Research institute in Novosibirsk.

The experts say there is a lack of published scientific work on the Baikal Rift Zone.

Only parts of it have been examined by geologists, while information has been synthesized only for the zone's centre, namely the Lake Baikal depression.

Novosibirsk researchers made a logical connection between tectonic processes and precipitation amassed in depressions or sinkholes of the Baikal Rift Zone that other teams had studied.

They concluded there was a network of rift depressions near the current Baikal rift during the Mesozoic Era, some 70-100 million years ago.

The Baikal Rift Zone developed smoothly tens of millions of years ago, until the second half of the Neogene Period.

At this point the speed of tectonic shifts suddenly escalated 5 to 7 million years ago. 

Mountains rose quickly, forming the region's striking ridges seen today, and depressions caved in, which led to the formation of an Alpine landscape.

The formation of the Alpine terrain was boosted by major periods of icing in the northern hemisphere, the first of which happened about 700,000 years ago, and the most recent of which 110,000 to 12,000 years ago.

'Decoding those processes, we can rebuild the tectonic schedule of Baikal rift zone within the last several dozen million years,' said Dr Krivonogov, who worked in partnership with Dr Inna Safonova, an expert in paleo-oceans and mantle magnetism from Novosibirsk State University.

'Many scientists worked at this task and I managed to combine and generalise the data, having added my own results. As a result, my article is a kind of review of the existing ideas on the structure and history of the depressions of Baikal rift zone.'

Over the period of human habitation, people gave different names to the spectacular lake which has held spiritual significance for many groups.

The Mongols called it Big Water, while the Chinese referred to it as the Northern Sea. The Russian trailblazers used the Evenki word ‘lamu’, which means sea. But the Turkic word Baikal - Rich Lake - has ultimately prevailed. 

The lake is a UNESCO World Heritage.

The Sobolev Institute is part of the Siberian Branch of Russian Academy of Sciences.