Distribution of permafrost and gas hydrates in relation to intensive gas emission in the central part of the Laptev Sea (Russian Arctic)

2022 ◽  
pp. 105527
Author(s):  
Vasily Bogoyavlensky ◽  
Aleksei Kishankov ◽  
Aleksei Kazanin ◽  
Gennady Kazanin
Keyword(s):  
Gas Hydrates ◽  
Laptev Sea ◽  
Russian Arctic ◽  
Gas Emission ◽  
The Laptev Sea

scholarly journals Earth degassing in the Arctic: comprehensive analysis of factors of powerful gas emission in the Laptev Sea

2021 ◽  
Vol 11 (2) ◽  
pp. 178-194
Author(s):  
V.I. Bogoyavlensky ◽  
◽  
A.G. Kazanin ◽  
A.V. Kishankov ◽  
G.A. Kazanin ◽  
...  
Keyword(s):  
Gas Hydrates ◽  
Average Distance ◽  
Comprehensive Analysis ◽  
The Arctic ◽  
Laptev Sea ◽  
Gas Emission ◽  
Bottom Simulating Reflector ◽  
Seismic Sections ◽  
First Time ◽  
The Laptev Sea

Interpretation was conducted for 28 CDP seismic time sections with total length of 5930 km acquired by JSC “MAGE” in the Central Laptev Area, where a zone of powerful gas emission had been discovered earlier. 519 anomalous objects were revealed in near-bottom deposits with an average distance on seismic lines of 11,4 km, potentially connected with accumulations of gas and its migration paths. As a result of comprehensive analysis, for the first time, connection of gas seeps with deep-seated faults in the study area was justified. Highly likely forecast was made that in the area of the discovered seeps (seafloor depths from 50—60 m to 110 m), permafrost and gas hydrates are absent, and the seeps are caused by direct migration of gas from great depths. On the continental slope of the Laptev Sea, a bottom simulating reflector (BSR) was distinguished in CDP seismic sections, associated with the base of gas hydrates.

scholarly journals Bioindication of the water salinity dynamics by the microalgae communities in the Lena River Delta, Laptev Sea, Russian Arctic

2021 ◽  
Vol 6 (3) ◽  
pp. 15-28
Author(s):  
S. S. Barinova ◽  
V. A. Gabyshev ◽  
A. P. Ivanova ◽  
O. I. Gabysheva
Keyword(s):  
Species Composition ◽  
River Delta ◽  
Water Bodies ◽  
Water Salinity ◽  
The Arctic ◽  
Laptev Sea ◽  
Russian Arctic ◽  
Lena River ◽  
Lena River Delta ◽  
The Laptev Sea

The Lena River in the Laptev Sea forms a vast delta, one of the largest in the world. The Ust-Lensky State Nature Reserve saves biodiversity on the Lena Delta territory beyond the Arctic Circle, in the zone of continuous permafrost. In recent years, large-scale plans for the development of extractive industries are implemented in this Russian Arctic sector. In this regard, the study of biodiversity and bioindication properties of aquatic organisms in the Lena River estuary area is becoming more and more relevant. This study aims to identify the species composition of microalgae in lotic and lentic water bodies of the Lena River Delta and use their indicator property for water salinity. It was a trace indicator of species distribution over the delta and their dynamics along the delta main watercourses to assess the impact of river waters on the Laptev Sea coastal areas. For this, all previously published materials on algae and chemical composition of the region waters as well as data obtained in recent years for the waters of the lower Lena reach were involved. In total, 700 species considered to 10 phyla were analyzed: Cyanobacteria (83), Euglenozoa (13), Ochrophyta (Chrysophyta, Xanthophyta) (41), Eustigmatophyta (4), Bacillariophyta (297), Miozoa (20), Cryptophyta (3), Rhodophyta (1), Chlorophyta (125), and Charophyta (111). The available materials of the field and reference observations were analyzed using several statistical methods. The study results indicate that hydrological conditions are the main factor regulating the spatial structure of the species composition of the microalgae communities in the Lena River Delta. The distribution of groups of salinity indicators across flowing water bodies reflects the effect of water salinity, and this allows suggesting possible sources of this effect. The mechanism of tracking the distribution of environmental indicators itself is a sensitive method, that reveals even their subtle changes in them; therefore, as an integral method, it can be helpful for further monitoring.

scholarly journals The Mesozoic–Cenozoic tectonic evolution of the New Siberian Islands, NE Russia

2014 ◽  
Vol 152 (3) ◽  
pp. 480-491 ◽  
Author(s):  
CHRISTIAN BRANDES ◽  
KARSTEN PIEPJOHN ◽  
DIETER FRANKE ◽  
NIKOLAY SOBOLEV ◽  
CHRISTOPH GAEDICKE
Keyword(s):  
Tectonic Evolution ◽  
Structural Evolution ◽  
Arctic Shelf ◽  
Laptev Sea ◽  
Russian Arctic ◽  
Thrust Belt ◽  
Fold Belt ◽  
New Siberian Islands ◽  
Ne Russia ◽  
The Laptev Sea

AbstractOn the New Siberian Islands the rocks of the east Russian Arctic shelf are exposed and allow an assessment of the structural evolution of the region. Tectonic fabrics provide evidence of three palaeo-shortening directions (NE–SW, WNW–ESE and NNW–SSE to NNE–SSW) and one set of palaeo-extension directions revealed a NE–SW to NNE–SSW direction. The contractional deformation is most likely the expression of the Cretaceous formation of the South Anyui fold–thrust belt. The NE–SW shortening is the most prominent tectonic phase in the study area. The WNW–ESE and NNW–SSE to NNE–SSW-oriented palaeo-shortening directions are also most likely related to fold belt formation; the latter might also have resulted from a bend in the suture zone. The younger Cenozoic NE–SW to NNE–SSW extensional direction is interpreted as a consequence of rifting in the Laptev Sea.

Structure and geology of the continental shelf of the Laptev Sea, Eastern Russian Arctic

1998 ◽  
Vol 298 (4) ◽  
pp. 357-393 ◽  
Author(s):  
Sergei S Drachev ◽  
Leonid A Savostin ◽  
Victor G Groshev ◽  
Inna E Bruni
Keyword(s):  
Continental Shelf ◽  
Laptev Sea ◽  
Russian Arctic ◽  
The Laptev Sea

Permafrost, Gas Hydrates and Gas Seeps in the Central Part of the Laptev Sea

2021 ◽  
Vol 500 (1) ◽  
pp. 766-771
Author(s):  
V. I. Bogoyavlensky ◽  
A. V. Kishankov ◽  
A. G. Kazanin
Keyword(s):  
Gas Hydrates ◽  
Laptev Sea ◽  
The Laptev Sea ◽  
Gas Seeps

scholarly journals Halogen-based reconstruction of Russian Arctic sea ice area from the Akademii Nauk ice core (Severnaya Zemlya)

2016 ◽  
Vol 10 (1) ◽  
pp. 245-256 ◽  
Author(s):  
A. Spolaor ◽  
T. Opel ◽  
J. R. McConnell ◽  
O. J. Maselli ◽  
G. Spreen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Laptev Sea ◽  
Russian Arctic ◽  
Ice Dynamics ◽  
Spring Sea Ice ◽  
Severnaya Zemlya ◽  
The Laptev Sea

Abstract. The role of sea ice in the Earth climate system is still under debate, although it is known to influence albedo, ocean circulation, and atmosphere–ocean heat and gas exchange. Here we present a reconstruction of 1950 to 1998 AD sea ice in the Laptev Sea based on the Akademii Nauk ice core (Severnaya Zemlya, Russian Arctic). The chemistry of halogens bromine (Br) and iodine (I) is strongly active and influenced by sea ice dynamics, in terms of physical, chemical and biological process. Bromine reacts on the sea ice surface in autocatalyzing "bromine explosion" events, causing an enrichment of the Br / Na ratio and hence a bromine excess (Brexc) in snow compared to that in seawater. Iodine is suggested to be emitted from algal communities growing under sea ice. The results suggest a connection between Brexc and spring sea ice area, as well as a connection between iodine concentration and summer sea ice area. The correlation coefficients obtained between Brexc and spring sea ice (r  =  0.44) as well as between iodine and summer sea ice (r  =  0.50) for the Laptev Sea suggest that these two halogens could become good candidates for extended reconstructions of past sea ice changes in the Arctic.

scholarly journals Factors Affecting the Formation and Evolution of Permafrost and Stability Zone of Gas Hydrates: Case Study of the Laptev Sea

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 504
Author(s):  
Tatiana V. Matveeva ◽  
Valery D. Kaminsky ◽  
Anastasiia A. Semenova ◽  
Nikolai A. Shchur
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Laptev Sea ◽  
Permafrost Degradation ◽  
Associated Gas ◽  
Gas Hydrate Formation ◽  
The Impact ◽  
The Laptev Sea ◽  
Hydrate Stability

The key factors controlling the formation and dynamics of relicpermafrost and the conditions for the stability of associated gas hydrates have been investigated using numerical modeling in this work. A comparison was made between two scenarios that differed in the length of freezing periods and corresponding temperature shifts to assess the impact on the evolution of the permafrost–hydrate system and to predict its distribution and geometry. The simulation setup included the specific heat of gas hydrate formation and ice melting. Significantly, it was shown that the paleoscenario and heat flows affect the formation of permafrost and the conditions for gas hydrate stability. In the Laptev Sea, the minimum and maximum predicted preservation times for permafrost are 9 and 36.6 kyr, respectively, whereas the presence of conditions consistent with methane hydrate stability at the maximum permafrost thickness is possible for another 25.9 kyr. The main factors influencing the rate of permafrost degradation are the heat flow and porosity of frozen sediments. The rates of permafrost thawing are estimated to be between 1 and 3 cm/yr. It is revealed that the presence of gas hydrates slows the thawing of the permafrost and feeds back to prolong the conditions under which gas hydrates are stable.

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