In-situ temperatures and thermal properties of the East Siberian Arctic shelf sediments: Key input for understanding the dynamics of subsea permafrost

Chuvilin, Evgeny; Bukhanov, Boris; Yurchenko, A. Yu.; Davletshina, Dinara; Shakhova, Natalia; Spivak, Eduard; Rusakov, V. Yu.; Dudarev, Oleg V.; Khaustova, N.; Тихонова, Анна; Gustafsson, Örjan; Tesi, Tommaso; Martens, Jannik; Spasennykh, М.; Semiletov, I. P.

doi:10.1016/j.marpetgeo.2022.105550

Cited by 10 publications

(3 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that the highest seabed microbial methane flux should be in the near shore area where the sediment has been warmed up, but the remaining amount of organic carbon is still high. Such prediction matches the observed hotspots of bottom water dissolved methane located near the coast of the Laptev Sea, the East Siberian Arctic Sea and the Beaufort Sea (Chuvilin et al, 2022;Lorenson et al, 2016;Shakhova et al, 2015). This further indicates that the bottom water methane comes from the biodegradation of the previously frozen organic carbon in the thawing subsea permafrost.…”

Section: Biodegradation Of the Ancient Organic Carbon As A Source Of ...supporting

confidence: 83%

See 1 more Smart Citation

Biodegradation of Ancient Organic Carbon Fuels Seabed Methane Emission at the Arctic Continental Shelves

You

2024

Global Biogeochemical Cycles

View full text Add to dashboard Cite

This study explores the carbon stability in the Arctic permafrost following the sea‐level transgression since the Last Glacial Maximum (LGM). The Arctic permafrost stores a significant amount of organic carbon sequestered as frozen particulate organic carbon, solid methane hydrate and free methane gas. Post‐LGM sea‐level transgression resulted in ocean water, which is up to 20°C warmer compared to the average annual air mass, inundating, and thawing the permafrost. This study develops a one‐dimensional multiphase flow, multicomponent transport numerical model and apply it to investigate the coupled thermal, hydraulic, microbial, and chemical processes occurring in the thawing subsea permafrost. Results show that microbial methane is produced and vented to the seawater immediately upon the flooding of the Arctic continental shelves. This microbial methane is generated by the biodegradation of the previously frozen organic carbon. The maximum seabed methane flux is predicted in the shallow water where the sediment has been warmed up, but the remaining amount of organic carbon is still high. It is less likely to cause seabed methane emission by methane hydrate dissociation. Such a situation only happens when there is a very shallow (∼200 m depth) intra‐permafrost methane hydrate, the occurrence of which is limited. This study provides insights into the limits of methane release from the ongoing flooding of the Arctic permafrost, which is critical to understand the role of the Arctic permafrost in the carbon cycle, ocean chemistry and climate change.

show abstract

Section: Biodegradation Of the Ancient Organic Carbon As A Source Of ...supporting

confidence: 83%

“…Temperature at the top of the domain is immediately increased to the bottom water temperature, −1.3°C, upon the flooding at 18 Kyr BP (Chuvilin et al., 2022; Nicolsky et al., 2012). After that, the temperature is kept constant at the seafloor until the present (0 Kyr).…”

Section: Simulating Carbon Stability In the Thawing Subsea Permafrostmentioning

confidence: 99%

Biodegradation of Ancient Organic Carbon Fuels Seabed Methane Emission at the Arctic Continental Shelves

You

2024

Global Biogeochemical Cycles

View full text Add to dashboard Cite

show abstract

“…As a result, the permafrost bottom accelerated to deepen and eventually pushed the freezing point isotherm downward to the base of the Iperk Sequence since the early Pleistocene sea-level retreat (Figure 5A), whereby the permafrost thickness kept growing until 1 Ma ago. Under the impermeable section provided by the thick permafrost (Chuvilin et al, 2022), super-saturated dissolved CH 4 could be stored in form of GHs and prevented from escaping through upper sequences into the atmosphere. Overall, Figure 5 implies that there may be a time window allowing for the formation of thick permafrost during the past 1.6 Ma to 1.0 Ma, and the subsequent genesis of sub-permafrost GH occurrences since 1.0 MaBP.…”

Section: Numerical Model Geometry and Parametrizationmentioning

confidence: 99%

Geologic controls on the genesis of the Arctic permafrost and sub-permafrost methane hydrate-bearing system in the Beaufort–Mackenzie Delta

Chabab

Spangenberg

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

The Canadian Mackenzie Delta exhibits a high volume of proven sub-permafrost gas hydrates that naturally trap a significant amount of deep-sourced thermogenic methane (CH4) at the Mallik site. The present study aims to validate the proposed Arctic sub-permafrost gas hydrate formation mechanism, implying that CH4-rich fluids were vertically transported from deep overpressurized zones via geologic fault systems and formed the present-day observed GH deposit since the Late Pleistocene. Given this hypothesis, the coastal permafrost began to form since the early Pleistocene sea-level retreat, steadily increasing in thickness until 1 Million years (Ma) ago. Data from well logs and 2D seismic profiles were digitized to establish the first field-scale static geologic 3D model of the Mallik site, and to comprehensively study the genesis of the permafrost and its associated GH system. The implemented 3D model considers the spatially heterogeneously distributed hydraulic properties of the individual lithologies at the Mallik site. Simulations using a proven thermo-hydro-chemical numerical framework were employed to gain insights into the hydrogeologic role of the regional fault systems in view of the CH4-rich fluid migration and the geologic controls on the spatial extent of the sub-permafrost GH accumulations during the past 1 Ma. For >87% of the Mallik well sections, the predicted permafrost thickness deviates from the observations by less than 0.8%, which validates the general model implementation. The simulated ice-bearing permafrost and GH interval thicknesses as well as sub-permafrost temperature profiles are consistent with the respective field observations, confirming our introduced hypothesis. The spatial distribution of GHs is a result of the comprehensive interaction between various processes, including the source-gas generation rate, subsurface temperature, and the hydraulic properties of the structural geologic features. Overall, the good agreement between simulations and observations demonstrates that the present study provides a valid representation of the geologic controls driving the complex permafrost-GH system. The model’s applicability for the prediction of GH deposits in permafrost settings in terms of their thicknesses and saturations can provide relevant contributions to future GH exploration and exploitation.

show abstract

Subsea permafrost and associated methane hydrate stability zone: how long can they survive in the future?

Malakhova,

Eliseev

2024

Theor Appl Climatol

View full text Add to dashboard Cite

In-situ temperatures and thermal properties of the East Siberian Arctic shelf sediments: Key input for understanding the dynamics of subsea permafrost

Cited by 10 publications

References 54 publications

Biodegradation of Ancient Organic Carbon Fuels Seabed Methane Emission at the Arctic Continental Shelves

Biodegradation of Ancient Organic Carbon Fuels Seabed Methane Emission at the Arctic Continental Shelves

Geologic controls on the genesis of the Arctic permafrost and sub-permafrost methane hydrate-bearing system in the Beaufort–Mackenzie Delta

Subsea permafrost and associated methane hydrate stability zone: how long can they survive in the future?

Contact Info

Product

Resources

About