
NSF Org: |
OPP Office of Polar Programs (OPP) |
Recipient: |
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Initial Amendment Date: | August 5, 2010 |
Latest Amendment Date: | August 5, 2010 |
Award Number: | 1023233 |
Award Instrument: | Standard Grant |
Program Manager: |
Neil R. Swanberg
OPP Office of Polar Programs (OPP) GEO Directorate for Geosciences |
Start Date: | August 15, 2010 |
End Date: | July 31, 2015 (Estimated) |
Total Intended Award Amount: | $291,353.00 |
Total Awarded Amount to Date: | $291,353.00 |
Funds Obligated to Date: |
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History of Investigator: |
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Recipient Sponsored Research Office: |
202 HIMES HALL BATON ROUGE LA US 70803-0001 (225)578-2760 |
Sponsor Congressional District: |
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Primary Place of Performance: |
202 HIMES HALL BATON ROUGE LA US 70803-0001 |
Primary Place of
Performance Congressional District: |
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Unique Entity Identifier (UEI): |
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Parent UEI: |
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NSF Program(s): | ANS-Arctic Natural Sciences |
Primary Program Source: |
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Program Reference Code(s): |
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Program Element Code(s): |
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Award Agency Code: | 4900 |
Fund Agency Code: | 4900 |
Assistance Listing Number(s): | 47.078 |
ABSTRACT
The Greenland Ice Sheet (GrIS) is the largest freshwater reservoir in the Arctic. Melting of the GrIS is increasing, delivering large amounts of freshwater to the Arctic Ocean. The nature and composition of microbial communities below the GrIS are not known, but recent studies have documented the presence of viable microbial communities in other subglacial environments and within the GrIS ice itself, indicating their potential importance for chemical weathering processes. This project will characterize GrIS? subglacial microbial communities to investigate the effect of microbes on lithospheric weathering and nutrient fluxes from the GrIS margin in West Greenland. The hypothesis is that the glacial thermal regime and bedrock lithology are the primary determinants of the subglacial bacterial communities, which in turn mediate nutrient release and weathering rates. Study sites in the Thule and Kangerlusuaq areas cover two major lithologies of West Greenland. The study combines state-of-the art microbiological, biogeochemical techniques, and datalogging of stream and climate parameters, to examine glacial meltwater.
It is anticipated that the melting of the GrIS will have large effects on global biogeochemical cycles, ocean ecology, and atmospheric CO2. GrIS subglacial microbes are anticipated to play an important role in mobilizing elements from the lithosphere. Data generated on the diversity of GrIS microbes (Bacteria, Archaea and Eukarya) will provide an initial assessment of microbial richness and diversity in aquatic habitats beneath the GrIS. The primary objective is to examine the biodiversity and microbial contribution to geochemical processes and nutrient release, and this study will also provide insight into low temperature adaptation of life in and to a hitherto unexamined subglacial environment. A synergistic relationship with the WISSARD (Whillams Ice Stream Subglacial Access Research Drilling) project will provide the opportunity for a bipolar comparison of biodiversity beneath the Greenland and West Antarctic ice sheets. Providing data of chemical composition and fluxes of meltwater (particularly carbon, iron and trace nutrients) and sediments released by the GrIS will provide a framework to assess potential feedbacks in global biogeochemical models. Detailed measurements over two melting seasons will provide fundamental data towards a conceptual model of GrIS? subglacial microbial environments.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The Greenland Ice Sheet is the largest freshwater reservoir in the northern hemisphere and its marginal ablation zones are degrading at an accelerated rate. Microbial metabolism in aquatic and sedimentary regions beneath the ice sheet will affect the composition of glacial outflow, possibly representing important sources of bioavailable micronutrients (e.g. reactive Fe) for nearby water masses as well as atmospheric greenhouse gases (e.g. CH4). We found that subglacial water discharged from the western margin of the Greenland Ice Sheet contained significant concentrations of dissolved methane (2.7 to 83 μM). Further, the most abundant microorganisms inhabiting this subglacial microbial community were bacteria that have the capacity to use methane as a carbon and energy source. These results suggest that microbial communities poised in oxygenated subglacial drainage channels at the margin of ice sheets could serve as significant methane sinks. The methane present in the outflows could be from contemporary microbial processes or may have been released from thawing sediments that stored methane previously. In the latter scenario, there is potential for the release of large amounts of methane with greater thawing. The education and outreach theme of this projected have revolved around a central question: what lives and happens under the ice sheets? Exploring subglacial environments as a ‘final frontier’ in the study of life in the subsurface biosphere is highly relevant given the need for collection of baseline data on subglacial conditions proximal to the ice sheet margin.
Last Modified: 11/20/2015
Modified by: Brent C Christner
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