ONE Planet DTP - Glaciers and ice sheets: pressurized nutrient bioreactors for the oceans (OP202061)

Subglacial water outflowing from under glaciers and ice sheets can be an important source of otherwise limiting nutrients such as P, Si and Fe for supporting productivity and CO2 drawdown in marine ecosystems (Death et al., 2014 Biogeosciences, 11, 2635-2643). To date, the fluxes and controls on nutrient production and export from ice sheets and their interactions with climate are poorly constrained over glacial cycles. A University of Bristol/Newcastle University grant (‘CRUSH2LIFE’, 2018-2021, NERC, £720K) is studying how ‘mechanochemical’ reactions (physical breaking of mineral bonds during rock crushing and subsequent free radical reactions; Telling et al., 2015, Nature 8, 851–855) can support subglacial microbial activity and promote nutrient cycling beneath glaciers and ice sheets. A PhD student is urgently required to work alongside this high profile project and study how pressure controls the rates and products of subglacial abiotic and biological reactions and their impact on ecosystem dynamics and nutrient supply. A key Project Partner is the US Subglacial Antarctic Lakes Access (SALSA) team, with collaboration with a drilling campaign into subglacial Lake Mercer (https://salsa-antarctica.org/study-area/) giving a unique ‘window’ into sub ice sheet biogeochemistry under Antarctica. Samples will be available from Lake Mercer and a range of other previously sampled subglacial environments. The PhD student will gain skills in state-of-the-art low temperature/high pressure experimentation, analytical geochemistry techniques, next generating sequencing, metagenomics/bioinformatics, and geochemical modelling. The student will gain experience of working as part of a larger multidisciplinary team. There may be the potential for glacier fieldwork during the project.