EDML ice-core volcanic sulfate concentration and deposition from 78.97 to 79.97 ka BP

Abstract

We present continuous records of ca. 2 cm resolved sulfate concentrations using a Continuous Flow Analysis (CFA) system (Röthlisberger et al., 2000; Severi et al., 2007; Wegner et al., 2015) from the EPICA Dronning Maud Land (EDML; 75.00°S, 00.07°E; 2892 m a.s.l.) ice core and estimated volcanic sulfate mass depositions for the time period 78.97 to 79.97 ka BP on the AICC2012 chronology (Veres et al., 2013) using a common volcanic marker in EDC dated 79.51 ka BP. The reconstruction is based on sulfate measurements employing high-resolution continuous flow analysis coupled to Fast Ion Chromatography. Volcanic eruptions are detected when annual sulfur concentrations exceeded the background concentrations + 4 times the median of the absolute deviation. Background concentrations are estimated using a 101-point running median. Volcanic sulfate deposition rates are calculated by subtracting the background concentrations from total sulfate concentrations using thinning corrected estimates of mean ice accumulation rates at the ice-core site.