Fe²⁺ in ice cores as a new potential proxy to detect past volcanic eruptions

• Published in: Science of The Total Environment
• Main Authors: Burgay, François, Erhardt, Tobias, Lunga, Damiano Della, Jensen, Camilla Marie, Spolaor, Andrea, Vallelonga, Paul, Fischer, Hubertus, Barbante, Carlo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2019
• Subjects: 530 Physics; Greenland; Greenland ice core; ice core
• Online Access: https://boris.unibe.ch/122003/1/burgaya18ste.pdf; https://boris.unibe.ch/122003/

Volcanic eruptions are widely used in ice core science to date or synchronize ice cores. Volcanoes emit large amounts of SO₂ that is subsequently converted inthe atmosphere into sulfuric acid/sulphate.Its discrete and continuous quantification is currently used to determine the ice layers impacted by volcanic emissions, but available high-resolution sulphate quantification methods in ice core (Continuous Flow Analysis (CFA)) struggle with insufficient sensitivity. Here, we present a new high-resolution CFA chemiluminescence method for the continuous determination of Fe²⁺ species in ice cores thatshowsclear Fe²⁺ peaks concurrent with volcanicsulphate peaks in the ice core record. The method, applied on a Greenland ice core, correctly identifies all volcanic eruptions from between 1588 to 1611 and from 1777 to 1850. The method has a detection limit of ∽5pgg⁻¹ and a quadratic polynomial calibration range of up to at least 1760 pg g⁻¹. Our results show that Fe²⁺ is a suitable proxy for identifying past volcanic events.