Dependence of ice-core relative trace-element concentration on acidification. Issue 219 (2014)

• Record Type: Journal Article
• Authors: Koffman, Bess G.; Handley, Michael J.; Osterberg, Erich C.; Wells, Mark L.; Kreutz, Karl J.
• Is Part Of: Journal of Glaciology. Volume 60:Issue 219(2014)
• Page Start: 103
• Page End: 112
• Publication Date: 2014
• Subjects: ice and climate, -- snow and ice chemistry
• DOI: 10.3189/2014JoG13J137
• Languages: English
• ISSNs: 0022-1430

Abstract

Abstract: To assess the role of methodological differences on measured trace-element concentrations in ice cores, we developed an experiment to test the effects of acidification strength and time on dust dissolution using snow samples collected in West Antarctica and Alaska. We leached Antarctic samples for 3 months at room temperature using nitric acid at concentrations of 0.1, 1.0 and 10.0% (v/v). At selected intervals (20 min, 24 hours, 5 days, 14 days, 28 days, 56 days, 91 days) we analyzed 23 trace elements using inductively coupled plasma mass spectrometry. Concentrations of lithogenic elements scaled with acid strength and increased by 100–1380% in 3 months. Incongruent elemental dissolution caused significant variability in calculated crustal enrichment factors through time (factor of 1.3 (Pb) to 8.0 (Cs)). Using snow samples collected in Alaska and acidified at 1% (v/v) for 383 days, we found that the increase in lithogenic element concentration with time depends strongly on initial concentration, and varies by element (e.g. Fe linear regression slope = 1.66; r = 0.98). Our results demonstrate that relative trace-element concentrations measured in ice cores depend on the acidification method used.