Determination of aeolian transport rates of volcanic soils in Iceland

Abstract

Sandy deserts cover >20000km2 in Iceland, consisting primarily of volcanic materials with basaltic volcanic glass being the main constituent. Wind erosion is severe in the country, causing dust pollution with widespread aeolian redistribution affecting most Icelandic ecosystems and sand movement over vegetated areas in the form of advancing sand fronts. We quantified wind erosion, using BSNE field samplers and automated sensors over several years at two sites with contrasting environments. The study sites are Holsfjöll with andic soil materials in the arid northeast highlands (<400mm annual precipitation) and Geitasandur on sandy surfaces in the humid south lowlands (>1200mm). Both areas show similar annual aeolian transport of 120–>670kgm−1yr−1. Aeolian flux in storms at the NE site was 3–43kgm−1h−1 on average with up to >200kgm−1h−1 during gusts. Multiple regression shows potential flux of >200kgm−1h−1 during intense storms of >20ms−1 (at 2m height). The research shows major aeolian activity in the humid South Iceland. Height distribution curves indicate considerable transport high above the surface at both sites (>60cm). Stable height distribution curves for each location allow for measurements using single dust trap over long periods. The research explains the intense activity of advancing sand fronts in Iceland and the significance of continuously recharged sand sources for maintaining severe wind erosion in humid areas of Iceland.