Anaerobic oxidation of methane and sulphate reduction rates, hydrocarbons, sulphate and sulphide concentrations of sediment cores from the Larsen B embayment at the eastern site of the Antarctic Peninsula, supplement to: Niemann, Helge; Fischer, David; Graffe, Dorothea; Knittel, Katrin; Montiel, Américo; Heilmayer, Olaf; Nöthen, Kerstin; Pape, Thomas; Kasten, Sabine; Bohrmann, Gerhard; Boetius, Antje; Gutt, Julian (2009): Biogeochemistry of a low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica. Biogeosciences, 6, 2383-2395

DOI

First videographic indication of an Antarctic cold seep ecosystem was recently obtained from the collapsed Larsen B ice shelf, western Weddell Sea (Domack et al., 2005). Within the framework of the R/V Polarstern expedition ANTXXIII-8, we revisited this area for geochemical, microbiological and further videographical examinations. During two dives with ROV Cherokee (MARUM, Bremen), several bivalve shell agglomerations of the seep-associated, chemosynthetic clam Calyptogena sp. were found in the trough of the Crane and Evans glacier. The absence of living clam specimens indicates that the flux of sulphide and hence the seepage activity is diminished at present. This impression was further substantiated by our geochemical observations. Concentrations of thermogenic methane were moderately elevated with 2 µM in surface sediments of a clam patch, increasing up to 9 µM at a sediment depth of about 1 m in the bottom sections of the sediment cores. This correlated with a moderate decrease in sulphate from about 28 mM at the surface down to 23.4 mM, an increase in sulphide to up to 1.43 mM and elevated rates of the anaerobic oxidation of methane (AOM) of up to 600 pmol cm-3 d-1 at about 1 m below the seafloor. Molecular analyses indicate that methanotrophic archaea related to ANME-3 are the most likely candidates mediating AOM in sediments of the Larsen B seep.

Identifier
DOI https://doi.org/10.1594/PANGAEA.745450
Related Identifier https://doi.org/10.5194/bg-6-2383-2009
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.745450
Provenance
Creator Niemann, Helge; Fischer, David; Graffe, Dorothea; Knittel, Katrin; Montiel, Américo; Heilmayer, Olaf; Nöthen, Kerstin; Pape, Thomas; Kasten, Sabine; Bohrmann, Gerhard; Boetius, Antje; Gutt, Julian
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2009
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 10 datasets
Discipline Earth System Research
Spatial Coverage (-61.471W, -65.909S, -60.353E, -65.435N); Weddell Sea, Larsen-B
Temporal Coverage Begin 2007-01-12T16:23:00Z
Temporal Coverage End 2007-01-17T13:42:00Z