|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ПсковГУ |
||
Iron and nitrate-driven anaerobic methane oxidation in methane seep sediments of the Laptev Seaстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 23 января 2026 г.
- Авторы: Purgina D., Moiseeva Yu, Wild B., Guseva N., Gershelis E., Gustafsson O., Khvashevskaya A., Pakhomova S., Kholodov V., Dudarev O., Kosmach D., Chernykh D., Polivanova T., Gangnus I., Kurilenko A., Domaniuk A., Yakushev E., Semiletov I.
- Журнал: Chemical Geology
- Том: 699
- Номер: 123170
- Год издания: 2026
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- DOI: 10.1016/j.chemgeo.2025.123170
- Аннотация: The East Siberian Arctic Shelf (ESAS) is a significant source of atmospheric methane, and the coastal Laptev Seanear the Lena River Delta is a documented hotspot for methane seepage. While anaerobic oxidation of methane(AOM) acts as a critical biofilter, the specific pathways and electron acceptors driving this process in the uniqueriver-influenced settings of the Arctic remain poorly understood. The Lena River delivers substantial terrigenousnutrients to this region, contributing approximately 10 % of the total riverine nitrogen and 17 % of the iron inputto the Arctic Ocean. This study examines the hypothesis that these nutrient fluxes play a crucial role in regulatingAOM, a key process mitigating methane emissions. We compared the geochemical conditions at active methaneseep sites and background areas, with a special focus on nitrogen and iron compounds in bottom and pore waters.Our geochemical investigation reveals three key findings: (1) Methane concentrations were substantiallyelevated at seep sites (up to 3118 nM) compared to background areas (as low as 5.5 nM) and showed negativecorrelations with nitrate (NO3 ) and iron (Fe) concentrations. (2) A clear decoupling of the Fe–Mn cycles at seepsites, which was absent in background sediments, indicates the preferential utilization of reactive iron oxides inAOM (Fe-AOM). (3) A severe depletion of bioavailable nitrogen species was observed in seep zones, where nitrateand nitrite concentrations were 5.5-fold and 2-fold lower, respectively, than in background areas, suggestingactive nitrate/nitrite-dependent AOM (N-AOM).These findings demonstrate that on the nutrient-rich, river-influenced Laptev Sea shelf, AOM is primarilydriven not by canonical sulfate reduction, but by the reduction of nitrogen species and iron. This newly identifiedcoupling between riverine nutrient fluxes and AOM pathways represents a critical, yet previously overlooked,mechanism that could significantly suppress methane emissions from climate-sensitive Arctic shelves. To ourknowledge, this study provides the first comprehensive investigation of nitrogen and iron transformationmechanisms coupled with methane oxidation at the water-sediment interface in the cold seeps of the coastalLaptev Sea shelf.
- Добавил в систему: Гангнус Иван Александрович