Origin and fate of methane in the Eastern Tropical North Pacific oxygen minimum zone.

ABSTRACT: Oxygen minimum zones (OMZs) contain the largest pools of oceanic methane but its origin and fate are poorly understood. High-resolution (<15 m) water column profiles revealed a 300 m thick layer of elevated methane (20-105 nM) in the anoxic core of the largest OMZ, the Eastern Tropical North Pacific. Sediment core incubations identified a clear benthic methane source where the OMZ meets the continental shelf, between 350 and 650 m, with the flux reflecting the concentration of methane in the overlying anoxic water. Further incubations characterised a methanogenic potential in the presence of both porewater sulphate and nitrate of up to 88 nmol g^-1day^-1 in the sediment surface layer. In these methane-producing sediments, the majority (85%) of methyl coenzyme M reductas

SUBMITTER: Chronopoulou PM 

PROVIDER: S-EPMC5437358 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature