High Resolution XRF Sediment Analysis of Late Season Precipitation Events in a High Arctic Glaciated Watershed: Svalbard, Norway

Sediment transport in High Arctic watersheds have historically been dominated by melt-induced processes (Woo and McCann, 1994). However, in Svalbard, the last decade has experienced increased discharge variability and late season precipitation events (Nowak and Hodson, 2013). This study provides a detailed description of sedimentation corresponding to these late season precipitation events in Linnevatnet, western Spitsbergen. Annual sediment traps of three consecutive years (2011-2012, 2013-2014, and 2014-2015) were examined through the coupling of high-resolution X-ray fluorescence (XRF) analysis with lower resolution grain size and magnetic susceptibility measurements. Geochemical signatures were compared temporally and geographically across the basin. Zirconium counts and Fe/Ti ratios (Cuven et al., 2010) were used to delineate events and seasonal boundaries. All three years experienced heavy late season precipitation events, resulting in peaks of coarse sediment deposition coupled with variable Ca content. Principle Component Analysis was run on 10 elemental constituents (Al, Si, K, Ca, Ti, Mn, Fe, Rb, Sr, and Zr) in order to examine the relationship between them. The 2013-2014 year showed a strong relationship (PC1>0.5) between all 10 elements and the first principle component (PC1), suggesting the elements varied together. The 2013-2014 sediment budget was dominated (>40%) by a single late August precipitation event. Multiple late season precipitation events in 2011-2012 and 2014-2015, on the other hand, were characterized by increased variance in sediment geochemistry.