TOMSK, Sept 29 – RIA Tomsk. The Russian researchers were first-ever who paid attention that changes of underwater permafrost in the Arctic seas of Siberia can cardinally influence processes of global warming. Scientists of Tomsk Polytechnic University (TPU) told about what danger they found under permafrost of the Arctic shelf and how to fight against it.
First of all scientists (professors of Department of Geology and Minerals Prospecting TPU) Igor Semiletov and Natalya Shakhova emphasize: no, there is nothing about any global disaster planned directly for tomorrow. But researches of the Arctic are important and actual just because predict its options, in particular, at inaction of mankind.
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The matter is that one of the main reasons for global warming which, according to some forecasts, can lead to world accident, is so-called "greenhouse effect". Its essence that solar radiation, reaching Earth and being reflected from its surface, partially is kept with "film" of molecules of carbon dioxide and methane. As a result the ground layer of the atmosphere where we live becomes warmer and warmer.
The most part of the "film" consists of carbon dioxide, methane is the most effective part of "hotbed" (by different estimates it is 30-50 times more effective). Unlike carbon dioxide, natural methane is formed in the oxygen-free environment, in particular, in the soil or is thicker than rainfall at an ocean floor.
According to a popular belief, methane is formed generally because of human activity: enterprises, burning of fuel and other anthropogenic processes. Oceanic methane, according to this theory doesn't influence climate as, passing through thickness of water, it is oxidized by microbes and doesn't get to the atmosphere.
However the Russian scientists, for many years studying the East Siberian Arctic shelf, came to other conclusions.
"The atmospheric maximum of methane (the second greenhouse gas according its value) is not over multitudes of the northern hemisphere, where the main anthropogenic emissions are, but over the Arctic. There it is about 10% higher", - Semiletov tells.
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Professor of Department of Geology and Minerals Prospecting TPU, doctor of geographical sciences Igor Semiletov
And it, according to the scientists, can be only the beginning. The Arctic shelf, which area is about two million square kilometers, stores a huge amount of organic carbon of which methane and other hydrocarbon gases are formed. As methane is lighter than air, he aspires up regardless of pressure influencing it, and gaseous methane passes into a firm condition of hydrates at the lower bound of underwater permafrost.
The layer of substances formed at the bottom can have a thickness up to several kilometers, and thickness of the underwater permafrost constraining it is to several hundred meters.
Provided that the underwater permafrost heats up and disappears, hydrate comes back in a gaseous form, and methane gets to water. And as the East Siberian shelf is the widest and the shallowest in the world, gas passes thickness of water in some minutes and nevertheless gets to the atmosphere.
According to estimates of scientists, at least 17 million tons of methane a year get to the atmosphere from the East Siberian shelf now that is approximately twice more than emission of methane from all other part of the World Ocean.
"As a result of centuries-old contact of underwater permafrost with rather warm benthonic water the thermal regime changes, and in underwater permafrost the gas-removing ways are formed. It can leave simply - as from a champagne bottle when removed a stopper as gas is under pressure", - Shakhova noted.
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Professor of Department of Geology and Minerals Prospecting TPU, doctor of geological and mineralogical sciences Natalya Shakhova
Also destruction of permafrost on northern coast is important. Now the average speed of thawing is about three meters a year, but it can reach 20-50 meters at some places. As a result the huge number of erosive organic substance which is oxidized to carbon dioxide gets on the shelf and lowers acidity of waters strongly that in turn leads to dissolution of armors of ground organisms and cockleshells.
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Shakhova explained that in the last hundreds years release of methane sharply increased because of thawing of permafrost in the Arctic shelf. The land's temperature of permafrost was near minus 17 degrees, after some thousands years ago flooding it began to heat up with rather warm benthonic waters which temperature also increases recently.
The big Siberian rivers became one of the reasons of heating of benthonic waters: Ob, Yenisei, Lena, Kolyma and others. They not only become warmer because of natural factors (heating up in more southern regions and keeping heat to the mouth), but also become deeper – including due to thawing of land's permafrost.
The heat arriving from the center of Earth "spur on" the process of a crack in crust through which the permafrost is heated.
Both for climate, and for oil industry workers
The existing forecasts for global warming don't consider the most powerful potential impact of massive emission of methane in the Arctic.
"Our group, perhaps, is the only one which is engaged in an explanation of the formation mechanism of a planetary maximum of methane from 1990th years. Nobody and never studied biogeochemical consequences of an erosion of an ice complex in the sea. Paradox is that it already occurred on our shelf!" - Semiletov emphasized.
He explained that as a result of destruction of a permafrost layer acidulation of waters near the East Siberian shelf reached extreme values which in other regions of the World Ocean are expected not earlier than 2200.
Respectively, these changes are able to afford to predict to what consequences global warming will lead. The international scientific and educational laboratory of studying of carbon of the Arctic seas created in TPU is just engaged in monitoring of a condition of the shelf and an assessment of changes which can soon happen on the planet.
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In recent years three expeditions to the Arctic are already executed within work of the laboratory. In particular, TPU scientists together with 80 colleagues from the different countries made 100-day expedition on the East Siberian shelf on the only in the world scientific ice breaker "Oden".
Thus thawing of permafrost and the subsequent release of "greenhouse" gases is important not only because of climatic changes.
"The Arctic ocean for us now is a source of resources: fish, mammals - there is food supply for many animals, there is a transport way, it is number one as the power region. But we know about it very little", - Shakhova explained.
So, methane passing through the Arctic waters oxidizes them. And as a result the ocean itself destroys the ecosystem: water with the increased acidity destroys armors and bones of inhabitants of the North Sea.
Besides, by various estimates, the Siberian shelf contains in two-five times more hydrocarbons (natural gas and oil), than in the Persian Gulf. In the next years scientists should estimate volumes of the hydrocarbons more precisely which are stored under permafrost, and also to develop recommendations for those who will build the extracting platforms on the shelf.
"Gas pockets and gas are explosive in big concentration. There are some cases – for example, gas emission nearly led to the tragedy in the Pechora Sea. People should be armed with knowledge, have recommendations, and complex target researches of the East Siberian shelf that demands attraction of considerable means are necessary for this purpose", - Shakhova noted, having emphasized that TPU scientists can realize these tasks who are engaged in studying of hydrocarbon fields for many years.
The main thing is to think
Now scientists formulated four scenarios of global warming, considering "a factor of the Arctic". The most optimistic of them assumes gradual thawing of ices, the most unfavorable (and the most improbable) is sharp warming and global environmental disaster on elimination of consequences of which the sum equal to budgets of all countries of the world can be demanded.
It is possible to prevent or correct any of scenarios if to take measures in time. However experts are necessary who would understand a question not within one grant as it is accepted to work in the West, and rather deep to help society to find solutions of these problems.
The experts ready to work with problems of the Arctic shelf, are started preparing in TPU now. However, according to Semiletov scientists have to carry out big educational work – after all it seems that the Arctic is too far. And these problems don't concern people.
"It isn't pleasant to people that we warn them. But imagine, if you visit a doctor, and he is telling you: "You have a cancer, but everything will be good, it is possible to do nothing". <…> We are people, we hope that mind power will allow us not only to go by car to a supermarket, but also to resolve some environmental global issues", - Shakhova added.