ORCID

Abstract

Glacial systems entrain and transfer sediment, rich in essential nutrients, from continental sources to the ocean, where they are released by meltwater. In the Southern Ocean, primary producers are limited by the availability of micronutrients, like iron (Fe), so any increase in continental sediment supply could enhance primary productivity and subsequent drawdown of atmospheric CO2. Here we provide a systematic account of labile Fe concentrations in Antarctic continental sediments. Ferrihydrite and crystalline Fe (oxyhydr)oxides were extracted from 27 Antarctic samples collected from nunataks, lateral moraines and blue ice areas in the Sør Rondane Mountains, East Antarctica. We report ascorbate extractable Fe (FeA) in all samples and enhanced precipitation of dithionite extractable Fe (FeD) in subaerially exposed mountain sediments. Our results suggest that as temperatures rise and Antarctic glaciers thin, newly exposed rock surfaces could supply more bioavailable iron to glacier systems, and subsequently the Southern Ocean.

Publication Date

2025-11-24

Publication Title

Nature Communications

Volume

16

Issue

1

ISSN

2041-1723

Acceptance Date

2025-10-21

Deposit Date

2025-12-15

Funding

Antarctic fieldwork was funded by the Baillet Latour Antarctica Fellowship, awarded to K.W. in October 2018. The Polar Regions Department (UK) provided K.W. with a permit for rock collection in Antarctica (permit no. 24/2018). J.R.J. received funding from PROTECT, a European Union’s Horizon 2020 research and innovation program, under grant agreement No 869304. We are grateful for the help of all International Polar Foundation staff working at the Princess Elisabeth Antarctica research station and would like to note that data collection would not have been possible without the expert guidance of our field guide, and station doctor, Jacque Richon, as well as our enthusiastic field assistants James Linighan and Ross Winter. The authors are grateful for local air temperature data provided to them by Konrad Steffen (former Director of the Swiss Federal Institute for Forest, Snow and Landscape Research) who set up the AWS near Princess Elisabeth Antarctica Research Station. We thank technicians working within the Geography Department at Northumbria University for their assistance with sediment analyses and are appreciative of the constant development of free and accessible datasets and software packages used in this study: NASA Ocean Biology Processing Group MODIS-Aqua data65, the MeASURES ice velocities data set25, The Reference Elevation Model of Antarctica69, The Landsat Image Mosaic of Antarctica70 and Quantarctica68. Antarctic fieldwork was funded by the Baillet Latour Antarctica Fellowship, awarded to K.W. in October 2018. The Polar Regions Department (UK) provided K.W. with a permit for rock collection in Antarctica (permit no. 24/2018). J.R.J. received funding from PROTECT, a European Union’s Horizon 2020 research and innovation program, under grant agreement No 869304. We are grateful for the help of all International Polar Foundation staff working at the Princess Elisabeth Antarctica research station and would like to note that data collection would not have been possible without the expert guidance of our field guide, and station doctor, Jacque Richon, as well as our enthusiastic field assistants James Linighan and Ross Winter. The authors are grateful for local air temperature data provided to them by Konrad Steffen (former Director of the Swiss Federal Institute for Forest, Snow and Landscape Research) who set up the AWS near Princess Elisabeth Antarctica Research Station. We thank technicians working within the Geography Department at Northumbria University for their assistance with sediment analyses and are appreciative of the constant development of free and accessible datasets and software packages used in this study: NASA Ocean Biology Processing Group MODIS-Aqua data, the MeASURES ice velocities data set, The Reference Elevation Model of Antarctica, The Landsat Image Mosaic of Antarctica and Quantarctica.

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