Surface melting and chemical analysis of a firn core from South Georgia: Implications for future drilling sites and paleoenvironmental records

Abstract In 2015, a continuous 15.4 m snow/firn core was recovered from central South Georgia Island at ∼850 m a.s.l. All firn core samples were analyzed for major (Al, Ca, Mg, Na, K, Ti and Fe) and trace element concentrations (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, S, V, Cr, Mn, Co, Cu and Zn) and stable water isotopes. The chemical and isotopic signal is well preserved in the top 6.2 m of the core. Below this depth, down to the bottom of the core, signal dampening is observed in the majority of the elemental species making it difficult to distinguish a seasonal signal. Thirteen elements (As, Bi, Ca, Cd, Cu, K, Li, Mg, Na, Pb, S, Sr and Zn) have crustal enrichment factor values higher than 10 suggesting sources in addition to those found naturally in the crust. While this study shows that 850 m a.s.l. is not high enough to preserve a record including recent years, higher-elevation (>1250 m a.s.l.) glaciers may be likely candidates for ice core drilling to recover better-preserved, continuous, recent to past glaciochemical records.