Contemporary and past aeolian deposition rates in periglacial conditions (Ebba Valley, central Spitsbergen)

Abstract

Quantitative measurements of aeolian activity at high latitudes are not currently carried out on a large scale, even though these processes are important elements of the geomorphic system of polar regions, which are particularly affected by climate change. This study presents the results of aeolian deposition rates measured and calculated for one of the central Spitsbergen postglacial valleys (Ebba Valley). The results are based on seven summer season field campaigns (2012–2018), as well as on AMS 14C and OSL dating of niveo-aeolian and aeolian sediments. Contemporary mean aeolian deposition rates ranged from 0.1 to 22.9 g·m−2·day−1 over selected parts of the valley and averaged from 2.1 to 12.3 g·m−2·day−1 over the studied summer seasons. Interestingly strong relationships (r2 = 0.71, p = 0.017) between mean air temperature and mean aeolian deposition were observed, possibly indicating the importance of the source material delivered to the valley by fluvioglacial processes. Moreover, aeolian deposition dependence on the source material reflected in the local nature of the process was observed. Niveo-aeolian deposition rates were estimated for the period since the 11th century, through the Little Ice Age, till the second half of the 20th century and revealed a rather constant value of 0.05 cm per year. Since then, the niveo-aeolian deposition rate has significantly increased and equalled 0.3 cm per year, which may be related to rising air temperatures and associated pan-Arctic environmental changes.