nerc.ac.uk

The silicon cycle impacted by past ice sheets

Hawkings, Jon R.; Hatton, Jade E.; Hendry, Katharine R.; de Souza, Gregory F.; Wadham, Jemma L.; Ivanovic, Ruza; Kohler, Tyler J.; Stibal, Marek; Beaton, Alexander; Lamarche-Gagnon, Guillaume; Tedstone, Andrew; Hain, Mathis P.; Bagshaw, Elizabeth; Pike, Jennifer; Tranter, Martyn. 2018 The silicon cycle impacted by past ice sheets. Nature Communications, 9 (1). 10.1038/s41467-018-05689-1

Before downloading, please read NORA policies.
[thumbnail of s41467_018_05689_1.pdf]
Preview
Text
s41467_018_05689_1.pdf
Available under License Creative Commons Attribution 4.0.

Download (3MB) | Preview

Abstract/Summary

Globally averaged riverine silicon (Si) concentrations and isotope composition (δ30Si) may be affected by the expansion and retreat of large ice sheets during glacial−interglacial cycles. Here we provide evidence of this based on the δ30Si composition of meltwater runoff from a Greenland Ice Sheet catchment. Glacier runoff has the lightest δ30Si measured in running waters (−0.25 ± 0.12‰), significantly lower than nonglacial rivers (1.25 ± 0.68‰), such that the overall decline in glacial runoff since the Last Glacial Maximum (LGM) may explain 0.06–0.17‰ of the observed ocean δ30Si rise (0.5–1.0‰). A marine sediment core proximal to Iceland provides further evidence for transient, low-δ30Si meltwater pulses during glacial termination. Diatom Si uptake during the LGM was likely similar to present day due to an expanded Si inventory, which raises the possibility of a feedback between ice sheet expansion, enhanced Si export to the ocean and reduced CO2 concentration in the atmosphere, because of the importance of diatoms in the biological carbon pump.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1038/s41467-018-05689-1
ISSN: 2041-1723
Date made live: 27 Sep 2018 15:57 +0 (UTC)
URI: https://nora.nerc.ac.uk/id/eprint/521059

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...