The part played by glaciers and ice sheets in global nutrient cycling is only just starting to be appreciated. Importantly, the global riverine concentrations and isotope composition of silicon (Si) may be affected by the expansion and retreat of large ice sheets during glacial−interglacial cycles.
A new study led by our viper-hat wearing colleague Jon Hawkings from the University of Bristol and co-authored by a number of scientists from the UK, Switzerland, USA, and Czechia, including Tyler and Marek, shows that glacial systems act as a significant source of isotopically light Si, either directly via dissolved silica or indirectly as dissolvable amorphous silica attached to suspended particulates. The results suggest that glacial meltwater-derived Si inputs can drive significant changes in the ocean’s Si inventory on glacial/interglacial and deglacial timescales and affect the productivity of diatoms relative to other primary producers. These findings highlight the important role played by glacial meltwater in the marine Si cycle, aiding in our interpretation of palaeoceanographic proxies and our understanding of past and present carbon cycling.
Another paper from the great 2015 Camp Doom field season!
Hawkings JR, Hatton JE, Hendry KR, de Souza GF, Wadham JL, Ivanovic R, Kohler TJ, Stibal M, Beaton A, Lamarche-Gagnon G, Tedstone A, Hain M, Bagshaw E, Pike J, Tranter M (2018) The global silicon cycle impacted by past ice sheets. Nature Communications 9:3210 doi: 10.1038/s41467-018-05689-1