Dissolved gases in frozen basal water from the NGRIP borehole: implications for biogeochemical processes beneath the Greenland Ice Sheet
Responsible organisation
2012 (English)In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 35Article in journal (Refereed) Published
Abstract [en]
Little information exists on biogeochemical transformations in aquatic ecosystems beneath polar ice sheets (i.e., water-saturated sediments, streams, rivers, and lakes) and their role in global elemental cycles. Subglacial environments may represent important sources of atmospheric CO2 and/or CH4 during deglaciation, thus acting as amplifiers in the climate system. However, the role of subglacial environments in global climate processes has been difficult to assess given the absence of biogeochemical data from the basal zones of inland polar ice sheets. Here, we report on the concentrations of CO2, CH4, and H-2 in samples of refrozen basal water recovered at a depth of similar to 3,042 meters below the surface during the North Greenland Ice Core Project (NGRIP). CH4 and H-2 concentrations in the NGRIP samples were approximately 60- and 700-fold higher, respectively, relative to air-equilibrated water, whereas CO2 was similar to fivefold lower. Metabolic pathways such as (1) methanogenesis, (2) organic matter fermentation, carboxydotrophic, and/or methylotrophic activity, and (3) CO2 fixation provide plausible biotic explanations for the observed CH4, H-2,H- and CO2 concentrations, respectively.
Place, publisher, year, edition, pages
2012. Vol. 35
Keywords [en]
Ice sheets Subglacial environments Greenland Microbial biogeochemistry Greenhouse gases lake vostok glacial ice antarctica diversity environments origin core melt Biodiversity & Conservation Environmental Sciences & Ecology
Research subject
SWEDARCTIC 1997, NordGRIP 1997; SWEDARCTIC 1998, NordGRIP 1998; SWEDARCTIC 1999, NordGRIP 1999; SWEDARCTIC 2000, NordGRIP 2000; SWEDARCTIC 2001, NordGRIP 2001; SWEDARCTIC 2002, NordGRIP 2002; SWEDARCTIC 2003, NordGRIP 2003; SWEDARCTIC 2004, NordGRIP 2004
Identifiers
URN: urn:nbn:se:polar:diva-1891DOI: 10.1007/s00300-012-1198-zOAI: oai:DiVA.org:polar-1891DiVA, id: diva2:810696
Note
ISI Document Delivery No.: 025QV Times Cited: 4 Cited Reference Count: 35 Christner, Brent C. Montross, Galena G. Priscu, John C. NSF [OPP-0636828, OPP-0838941, OPP-1023233, OPP-0838933, OPP-0839075, OPP-1027284]; NASA [NAI5-0021]; FNU, Denmark; FNRS-CFB, Belgium; IPEV, France; INSU/CNRS, France; AWI, Germany; RannIs, Iceland; MEXT, Japan; SPRS, Sweden; SNF, Switzerland; NSF, Office of Polar Programs, USA The ice cores in this study were recovered during the NGRIP ice core project, which was directed by the Ice and Climate Research Group at the Niels Bohr Institute, University of Copenhagen and funded by agencies in Denmark (FNU), Belgium (FNRS-CFB), France (IPEV and INSU/CNRS), Germany (AWI), Iceland (RannIs), Japan (MEXT), Sweden (SPRS), Switzerland (SNF), and the USA (NSF, Office of Polar Programs). We especially acknowledge NGRIP project leader Dorthe Dahl-Jensen for organizing the NGRIP basal ice working group and providing ice core samples for analysis. We also thank D. Mogk and M. Skidmore for assistance with SEM-EDS, S. Busse for assistance with the NMR measurements and interpretation, and G. King for discussion. Travel funding for Brent C. Christner to visit the University of Copenhagen was provided by the Arctic Natural Sciences Program of the NSF. This study was partially supported by NSF grants OPP-0636828, OPP-0838941, and OPP-1023233 awarded to Brent C. Christner, and OPP-0838933, OPP-0839075, OPP-1027284 and NASA NAI5-0021 awarded to John C. Priscu. 4 Springer New york Biodiversity Conservation; Ecology
2015-05-082015-05-062017-12-04Bibliographically approved