As Antarctic glaciers thin, they expose nunataks, mountain peaks emerging from the ice, and those bare rock surfaces turn out to matter for the global carbon cycle. A study published in Nature Communications on 24 November 2025, led by Northumbria University with Newcastle University's Professor Stuart Dunning among the authors, analysed sediment from the Sor Rondane Mountains in East Antarctica and found it unusually rich in bioavailable iron.
Iron is the limiting nutrient across much of the Southern Ocean, so any new supply has outsized biological consequences. When iron-rich sediment reaches coastal waters it fertilises phytoplankton, the microscopic algae that draw carbon dioxide out of the atmosphere as they grow. The work draws on material collected during fieldwork in 2013, part of a project on ice sheet elevation change and rockfall debris, illustrating how long-horizon field science yields unexpected dividends.
The authors are careful with the caveats. The study covers a single glacier system, the wider effect on ocean carbon uptake remains unquantified, and the glacial conveyor moves slowly: sediment generated in the mountains may take between 10,000 and 100,000 years to reach the coast. The finding is less a near-term climate remedy than a correction to how models represent natural iron supply from a thawing continent.