Methane in West Siberia Terrestrial Seeps: Origin, Transport, and Metabolic Pathways of Production
Full article
Journal |
Global Change Biology
ISSN: 1365-2486
|
Output data |
Year: 2023,
Volume: 29,
Number: 18,
Pages: 5334-5351
Pages count
: 18
DOI:
10.1111/gcb.16863
|
Tags |
groundwater methane; metabolic pathways; methane biogeochemistry; northern peatlands; stable isotopes |
Authors |
Sabrekov Aleksandr F.
1,2
,
Terentieva Irina E.
3
,
McDermid Gregory J.
3
,
Litti Yuriy V.
4
,
Prokushkin Anatoly S.
5
,
Glagolev Mikhail V.
1,6
,
Petrozhitskiy Alexey V.
7,8
,
Kalinkin Peter N.
9
,
Kuleshov Dmitry V.
8,10
,
Parkhomchuk Ekaterina V.
8,10
|
Affiliations |
1 |
UNESCO Department “Environmental Dynamics and Global Climate Changes”, Ugra State University, Khanty-Mansiysk, Russia
|
2 |
V.N. Sukachev Laboratory of Biogeocenology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
|
3 |
Department of Geography, University of Calgary, Calgary, Canada
|
4 |
Laboratory of Microbiology of Anthropogenic Habitats, Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
|
5 |
Laboratory of Biogeochemical Cycles in Forest Ecosystems, VN Sukachev Institute of Forest SB RAS, Krasnoyarsk, Russia
|
6 |
Department of Physics and Reclamation, Faculty of Soil Science, Lomonosov Moscow State University, Moscow, Russia
|
7 |
Laboratory 5-2, Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
|
8 |
AMS Golden Valley, Novosibirsk State University, Novosibirsk, Russia
|
9 |
The Group of Template Synthesis, Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia
|
10 |
Laboratory AIsotope, Institute of Archaeology and Ethnography SB RAS, Novosibirsk, Russia
|
|
Funding (2)
1
|
Правительство Тюменской области
|
|
2
|
Russian Science Foundation
|
19-77-10074 (122032300076-2)
|
The expansive plains of West Siberia contain globally significant carbon stocks, with Earth's most extensive peatland complex overlying the world's largest-known hydrocarbon basin. Numerous terrestrial methane seeps have recently been discovered on this landscape, located along the floodplains of the Ob and Irtysh Rivers in hotspots covering more than 2500 km2. We articulated three hypotheses to explain the origin and migration pathways of methane within these seeps: (H1) uplift of Cretaceous-aged methane from deep petroleum reservoirs along faults and fractures, (H2) release of Oligocene-aged methane capped or trapped by degrading permafrost, and (H3) horizontal migration of Holocene-aged methane from surrounding peatlands. We tested these hypotheses using a range of geochemical tools on gas and water samples extracted from seeps, peatlands, and aquifers across the 120,000 km2 study area. Seep-gas composition, radiocarbon age, and stable isotope fingerprints favor the peatland hypothesis of seep-methane origin (H3). Organic matter in raised bogs is the primary source of seep methane, but observed variability in stable isotope composition and concentration suggest production in two divergent biogeochemical settings that support distinct metabolic pathways of methanogenesis. Comparison of these parameters in raised bogs and seeps indicates that the first is bogs, via CO2 reduction methanogenesis. The second setting is likely groundwater, where dissolved organic carbon from bogs is degraded via chemolithotrophic acetogenesis followed by acetate fermentation methanogenesis. Our findings highlight the importance of methane lateral migration in West Siberia's bog-dominated landscapes via intimate groundwater connections. The same phenomenon could occur in similar landscapes across the boreal-taiga biome, thereby making groundwater-fed rivers and springs potent methane sources.