"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
This study will use tracer methodologies to track the origin and extent of exogenous microbial contamination during ice-core drilling and post-core relaxation in order to ascertain the indigenous microbial diversity and its relationship to past climates and to nitrous oxide records. The project would be conducted during the drilling of the North Eemian (?NEEM?) deep ice core in Greenland. Specific objectives and methods include: (1) Testing the possible origin of microbial contamination from different sources using the following approaches: microbiological and molecular analyses of the drilling fluid, tracking its penetration into the ice by mass spectrometry, and testing the infiltration of potential contaminants by delivering fluorescent microspheres (acting as microbial surrogates) in the borehole during particular runs and analyzing thin sections of the microsphere coated ice cores by fluorescent microscopy and flow cytometry; (2) Using high resolution microscopic and flow cytometric techniques to determine the abundance, viability and diversity of the indigenous microbial populations from different depths in relationship to deposition climate; (3) Linking possible anomalies of the elemental and isotopic composition of nitrous oxide in ice dated between 35,000 and 45,000 years to microbial in-situ production by specific organisms.
