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

François Burgay; Tobias Erhardt; Damiano Della Lunga; Camilla Marie Jensen; Andrea Spolaor; Paul Vallelonga; Hubertus Fischer; Carlo Barbante

doi:10.1016/j.scitotenv.2018.11.075

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

Sci Total Environ. 2019 Mar 1:654:1110-1117. doi: 10.1016/j.scitotenv.2018.11.075. Epub 2018 Nov 7.

Authors

François Burgay¹, Tobias Erhardt², Damiano Della Lunga³, Camilla Marie Jensen², Andrea Spolaor⁴, Paul Vallelonga⁵, Hubertus Fischer², Carlo Barbante⁶

Affiliations

¹ Department on Environmental Science, Informatics and Statistics, Ca' Foscari, University of Venice, Venice, Italy. Electronic address: francois.burgay@unive.it.
² Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
³ Alfred Wegener Institute, Helmholtz-Zentrum fur Polar und Meeresforschung, Bremerhaven, Germany.
⁴ National Research Council, Institute for the Dynamics of Environmental Processes, Venice, Italy.
⁵ Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen K, Denmark.
⁶ Department on Environmental Science, Informatics and Statistics, Ca' Foscari, University of Venice, Venice, Italy; National Research Council, Institute for the Dynamics of Environmental Processes, Venice, Italy.

PMID: 30841386
DOI: 10.1016/j.scitotenv.2018.11.075

Abstract

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 in the 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 that shows clear Fe²⁺ peaks concurrent with volcanic sulphate 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 ∽5 pg g^-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.

Keywords: Chemiluminescence; Continuous flow analysis; Greenland; Iron speciation; Volcano.