Ice sheets as a missing source of silica to the polar oceans

• DOI: 10.1038/ncomms14198
• Publication Date: 2017-01-25T11:17:08Z
• Authors: Jon R. Hawkings; Jemma L. Wadham; Liane G. Benning; Katharine R. Hendry; Martyn Tranter; Andrew Tedstone; Peter Nienow; Rob Raiswell
• Keywords: Biogenic silica; Deglaciation; Meltwater; Dissolved silica; Greenland ice sheet

Abstract Ice sheets play a more important role in the global silicon cycle than previously appreciated. Input of dissolved and amorphous particulate silica into natural waters stimulates growth diatoms. Here we measure Greenland Sheet meltwaters icebergs, demonstrating potential for high ice sheet export. Our flux is 0.20 (0.06–0.79) Tmol year −1 , ∼50% input from Arctic rivers. Amorphous comprises >95% this highly soluble sea water, as indicated by significant increase across fjord salinity gradient. Retreating palaeo were therefore likely responsible fluxes ocean during last deglaciation, reaching values ∼5.5 similar to estimated export These elevated may explain diatom productivity observed glacial–interglacial period.