Environmental pressure from the 2014-15 eruption of Bardarbunga volcano, Iceland

The effusive six months long 2014-2015 Bardarbunga eruption (31 August- 27 February) was the largest in Iceland for more than 200 years, producing 1.6 +/- 0.3 km(3) of lava. The total SO2 emission was 11 +/- 5 Mt, more than the amount emitted from Europe in 2011. The ground level concentration of SO2 exceeded the 350 mu g m(-3) hourly average health limit over much of Iceland for days to weeks. Anomalously high SO2 concentrations were also measured at several locations in Europe in September. The lowest pH of fresh snowmelt at the eruption site was 3.3, and 3.2 in precipitation 105 km away from the source. Elevated dissolved H2SO4, HCl, HF, and metal concentrations were measured in snow and precipitation. Environmental pressures from the eruption and impacts on populated areas were reduced by its remoteness, timing, and the weather. The anticipated primary environmental pressure is on the surface waters, soils, and vegetation of Iceland.