The deepwater exploration of Lake Baikal by two MIR mini-submarines attracted global attention and has met with significant success.

Besides new kinds of worms inhabiting the deep waters, the submarines discovered a crack in the lakebed from which crude oil seeps into the lake. The risk of an environmental disaster threatening Baikal shouldn't be exaggerated, however.

The oil thread brings only around four metric tons into the lake annually and poses no threat to Baikal, which contains 23,000 cubic meters of water. Furthermore, the oil does not migrate far from the crack, as most of it is digested by bacteria inhabiting the lakebed.

Where does the oil come from? Several hypotheses have been proposed, but none yet proven. Oleg Sorokhtin, Ph.D.(Physics and Mathematics), of the Russian Academy of Sciences' Institute of Oceanology, told RIA Novosti about one of them: "Baikal is a split between lithosphere plates, which is surrounded by continents.

A huge amount of terrigenous material from rupturing continental rocks is constantly sliding into the split. Baikal's water is inhabited by lots of fish, shellfish and various kinds of phytoplankton, which after their lifecycle form organic-rich sediments at the bottom of the lake. These sediments are the raw material for the oil formation."

Petrogenesis, the formation of oil from organic matter, is a very complicated process from the technological point of view, and takes 25-30 million years.

Oleg Sorokhtin also said that abiogenous methane is likely to be found on the lake bed. The gas evolves from oxidation of material from the earth's interior rising through the split between continental plates. Mantle rock contains liquid iron, causing the emissions of methane, which is involved in the carbon cycle.

The Baikal oil crack is covered by a layer of sediment several kilometers thick. Oil is lighter than water and therefore goes up. The remains of the oil leaks, which are not digested by bacteria, sometimes form oil spots on the lake surface.

"The exploration mission is in itself very important for fundamental science, Oleg Sorokhtin says. "As for the presence of oil, I don't think there's much of it under the lake. The fact itself is very interesting. But we should stop when we find proof that oil is there. Oil production would be a crime here, even if huge reserves of oil are discovered. I hope this won't happen."

The opinions expressed in this article are the author's and do not necessarily represent those of RIA Novosti.