Scientists from Tomsk Polytechnic University summarized the current insights of the subsea permafrost–hydrate system under the conditions of modern warming in the East Siberian Arctic Shelf (ESAS). The outputs of 44 all-season expeditions carried out in the seas of the Eastern Arctic are the basis of the current understanding. The paper was published in Geosciences.
The study was conducted by TPU Professor Natalia Shakhova and TPU Professor Igor Semiletov together with the scientists from the Skolkovo Innovation Center.
Dr. Natalia Shakhova says:
‘The paper presents in detail different stages to pass towards the understanding as well as specific features peculiar to the formation and degradation of subsea permafrost and hydrates of the Arctic Shelf as a single system: from the first steps based on single measurements and simplified modeling schemes to summarizing the multi-year complex original data obtained by our scientific consortium over the past 25 years.’
According to Shakhova, for the first time, the group has critically analyzed the results obtained in different studies; the strengths and weaknesses of individual studies were shown to become the basis for a new strategic approach to the investigation of the unique East Siberian Arctic Shelf (ESAS). More than 80 % of the entire underwater permafrost on our planet is on this shelf. It is degrading at a progressive rate, which is crucial for the understanding of the subsea permafrost-hydrates system under the conditions of modern warming that is the most lasting over the last hundreds of thousands of years.
‘The paper provides the transformation principals of underwater permafrost and hydrates over the last climatic cycles. Furthermore, it demonstrates that the fundamental understanding of the role played by methane hydrates in the current and future climate conditions, being one of the major challenges of modern natural science, can only be gained through combined efforts of scientists from around the world. This is based on the understanding achieved by our consortium over many years of all-season studies,’ – says the professor.
Based on original long-term data Natalia Shakhova and co-authors came to the conclusion that the climatic periodicity of the change of cold and warm geological epochs was broken due to anthropogenic warming. This was manifested in the unprecedented high standing of water in the Arctic Shelf (as part of the World Ocean), which led to the progressive degradation of subsea permafrost, i.e. the immense supply of hydrates in seas of Eastern Arctic (SEA) via large-scale methane emissions from bottom sediments into the water column-atmosphere. In other words, climatic periodicity was broken: instead of cooling and sea level lowing after the Holocene warming optimum, which occurred in the Northern Hemisphere about 5-6 thousand years ago, further warming-melting of glaciers and sea level rise began to occur. All this caused the continuation of contact time of the subsea permafrost with relatively warm bottom water for thousands of years and further deepening of underwater permafrost in different areas of the SEA to the hydrate stability zone, which became a kind of trigger for new feedbacks in the Arctic climate system.
Professor Igor Semiletov emphasizes:
‘Currently, our group is the first to scientifically substantiate the fact that the periodicity change of a geological factor – a state of subsea permafrost – becomes a leading driver of the Arctic climate system functioning.
‘The rate at which methane content will increase in the atmosphere through the involvement of a giant hydrate reservoir into the modern biogeochemical cycle due to progressive degradation as a disruption of underwater permafrost’ is the issue that worries the entire population of our planet. It can be addressed only by developing the strategy outlined in our paper.’
Over a month following the publication, the paper was downloaded more than 4,000 times. According to bibliometric data, the paper hit 5 % of new publications that raised a profound international interest among the global community.