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Permafrost on the Arctic shelf thaws faster than expected

Permafrost on the Arctic shelf thaws faster than expected

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Photo: wikipedia.org

Date : Aug 09, 2017 02:51 PM

Thawing already leads to methane emissions from the bottom layers

An international group of scientists from Russia, the United States and Sweden came to the conclusion that underwater permafrost on the East Siberian Arctic shelf is thawing faster than expected earlier. The information disproves specialized climate organization at the UN which claims that the thawing of the shelf will not lead to changes in the environment in the 21st century.

The study is based on information obtained during the wells drilling on the Laptev Sea shelf. The researchers compared the information with the data obtained about thirty years ago. It has been found that rate of the underwater permafrost thawing can reach 18 centimeters per year. It is massively more than scientists from Arctic countries claimed.

The process of the permafrost destruction leads to the appearance of gas-evolving channels. Through these channels methane bursts out near bottom hydrate stores (a snow like compound of natural gas with water). «We come to the conclusion that in some areas of the East Siberian shelf the roof of the underwater permafrost has already reached the depth of the zone of hydrate stability, the destruction of which can lead to massive emissions of bubble methane,» told the Professor of the Geology Department in the Tomsk Polytechnic University (TPU) Natalya Shakhova.

Perhaps, the thawing explains the increased concentration of methane in the above-water atmosphere of the Eastern Arctic seas in 2-4 times compared with the average level of the planet, scientists believe.

Moreover, methane enters the atmosphere from the furrows, which leave icebergs on the shelf surface. It`s curious that in the Intergovernmental Panel on Climate Change (IPCC, the climate organization at the UN) forecasts stated that the permafrost in the Eastern Arctic is stable, which prevents the destabilization of a huge underwater cluster of methane hydrates, the representative of TPU explained.

The permafrost thaw can thereafter lead to hydrates explosions and catastrophic methane emissions. Earlier similar cases were noted in the Pechora Sea. Thawing permafrost may affect hydrocarbons production plans on the shelf, according to the study. In the future, the group of scientists plans to create models to predict natural disasters and to avoid incidents during the resources extraction. Hydrates stocks at the bottom of the East Siberian sea and the Laptev Sea have previously been estimated from 1 trillion to 9 trillion cubic meters as the gas volume.

Scientists from the Tyumen State University, Tomsk Polytechnic University, Moscow State University, Stockholm University, University of Alaska and from several institutes of Russian Academy of Sciences were involved in this study. The study results are published in Nature Communications.

Meanwhile, the People’s Republic of China government announced that they intend to start methane hydrate mining in the water areas near their borders.

 

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