Mercury mobilization and export from the Greenland Ice Sheet using an ice-to-ocean approach

Amina Nikol Youssef; Sarah E. Janssen; Carl Lamborg; Michael Tate; Marissa Despins; Eva L. Doting; Brett A. Poulin; David McCabe; Leah M. Hopf; Emma K. Ferrer; Abe Doroshow; Guillaume Lamarche-Gagnon; Ian Delaney; Marjolein Gevers; Jade Hatton; Iris Kubler-Dudgeon; Jack Geary Murphy; Amina T. Schartup; Marek Stibal; Johannes West; Jon R. Hawkings

doi:10.1038/s43247-026-03818-z

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Mercury mobilization and export from the Greenland Ice Sheet using an ice-to-ocean approach

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Abstract

The Greenland Ice Sheet (GrIS) is a poorly constrained source of mercury (Hg) to Arctic ecosystems. We measured Hg concentrations and stable isotopes along an ice-to-ocean continuum to identify controls on GrIS Hg export. Early-season permafrost melt and rainfall produced high filtered total mercury (fTHg, ~17 pM) and monomethylmercury (MMHg, ~2 pM). As subglacial drainage evolved, particulate Hg doubled (from ~8 to 17 pM) and MMHg production remained elevated, indicating Hg mobilization from subglacial environments. Shifts in Hg stable isotope ratios and Δ 199 Hg mass balance show supraglacial sources contribute 20–48% of exported Hg, suggesting subglacial inputs dominate the seasonal Hg flux. Fjord waters were enriched in fTHg ( ~ 10 pM) and MMHg ( ~ 2 pM) relative to rivers, consistent with particulate Hg transformations and terrestrial Hg inputs. The estimated GrIS Hg yield ( ~ 23 mmol km −2 yr −1 ) is similar to that of Arctic rivers and will likely increase with climate-driven mass loss.

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Communications Earth & Environment Article

Source-reported bounding extent: 64.90262959376048° to 67.5464558693183° latitude; -55.05186326527543° to -45.72541519944539° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Amina Nikol Youssef, Sarah E. Janssen, Carl Lamborg, Michael Tate, Marissa Despins, Eva L. Doting, Brett A. Poulin, David McCabe, Leah M. Hopf, Emma K. Ferrer, Abe Doroshow, Guillaume Lamarche-Gagnon, Ian Delaney, Marjolein Gevers, Jade Hatton, Iris Kubler-Dudgeon, Jack Geary Murphy, Amina T. Schartup, Marek Stibal, Johannes West, Jon R. Hawkings. 2026-07-16. Mercury mobilization and export from the Greenland Ice Sheet using an ice-to-ocean approach. https://doi.org/10.1038/s43247-026-03818-z

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