Professor of Polar Biogeochemistry
I have a long term research interest in the biogeochemical processes that impact on the compsoition of melt waters flowing on, in and under glaciers and ice sheets, and the chemical changes the water induces in the aerosol and debris it encounters. I was involved in the discovery of microbial life in subglacial environments, and leading the research consequences that this paradigm shift for the discipline has entailed. These include: (1) the production of labile forms of nutrients, such as Fe, from glacially crushed rock, which makes an important contribution ot the fertilisation of the Southern Ocean via ice berg rafting of debris; (2) the prediction of life in sub-ice sheet environments, sustained by REDOX processes resulting from the comminution of bedrock; and (3) the greater liklihood that life may be sustained in wet sub-icesheet environments in other ice-covered parts of the Universe.
A current area of great interest, championed by Jon Telling, is that some of the thermomechanical energy generated by the glacial erosion of silicate bedrock is converted in free radicals on the seared silicate and sulphide surfaces, which in turn generate a spectrum of oxidising and reducing agents when wetted, so potentially providing energy sources for a spectrum of subglacial microbes. A recent paper in Nature Geosciences (8, 851-855) provides evidence for the inorganic production of hydrogen gas in subglacial environments, and is the next potential paradigm shift in the study of subglacial biogeochemistry.
My work has also demonstrated that a spectrum of microorganisms actively grow and change the geocehmistry of waters on the surfaces of glaciers and ice sheets. The work has ultimately lead to the funding of the Black and Bloom project, which is about to test the hypothesis that pigmented algae growing on the surface of the Greenland Ice Sheet are causing darkening, which results in enhanced melting of the south west sector of the Ice Sheet.