Biolabile ferrous iron bearing nanoparticles in glacial sediments

Jon R. Hawkings*, Liane G. Benning, Rob Raiswell, Burkhard Kaulich, Tohru Araki, Majid Abyaneh, Anthony Stockdale, Monika Koch-Müller, Jemma L. Wadham, Martyn Tranter

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

22 Citations (Scopus)
315 Downloads (Pure)

Abstract

Glaciers and ice sheets are a significant source of nanoparticulate Fe, which is potentially important in sustaining the high productivity observed in the near-coastal regions proximal to terrestrial ice cover. However, the bioavailability of particulate iron is poorly understood, despite its importance in the ocean Fe inventory. We combined high-resolution imaging and spectroscopy to investigate the abundance, morphology and valence state of particulate iron in glacial sediments. Our results document the widespread occurrence of amorphous and Fe(II)-rich and Fe(II)-bearing nanoparticles in Arctic glacial meltwaters and iceberg debris, compared to Fe(III)-rich dominated particulates in an aeolian dust sample. Fe(II) is thought to be highly biolabile in marine environments. Our work shows that glacially derived Fe is more labile than previously assumed, and consequently that glaciers and ice sheets are therefore able to export potentially bioavailable Fe(II)-containing nanoparticulate material to downstream ecosystems, including those in a marine setting. Our findings provide further evidence that Greenland Ice Sheet meltwaters may provide biolabile particulate Fe that may fuel the large summer phytoplankton bloom in the Labrador Sea, and that Fe(II)-rich particulates from a region of very high productivity downstream of a polar ice sheet may be glacial in origin.

Original languageEnglish
Pages (from-to)92-101
Number of pages10
JournalEarth and Planetary Science Letters
Volume493
Early online date25 Apr 2018
DOIs
Publication statusPublished - 1 Jul 2018

Keywords

  • Arctic
  • biological pump
  • export-productivity
  • glaciers
  • iron
  • sediment

Fingerprint Dive into the research topics of 'Biolabile ferrous iron bearing nanoparticles in glacial sediments'. Together they form a unique fingerprint.

  • Projects

    Cite this

    Hawkings, J. R., Benning, L. G., Raiswell, R., Kaulich, B., Araki, T., Abyaneh, M., Stockdale, A., Koch-Müller, M., Wadham, J. L., & Tranter, M. (2018). Biolabile ferrous iron bearing nanoparticles in glacial sediments. Earth and Planetary Science Letters, 493, 92-101. https://doi.org/10.1016/j.epsl.2018.04.022