Sulphur dioxide emissions fall sharply, but Etna is still largest source of SO2 in Europe
European Space Agency (ESA) satellite data has shown that the levels of sulphur dioxide being released into the atmosphere by Mount Etna have fallen by up to four times since its initial eruption. Since its first big eruption on 27 October, Etna has continued to release huge plumes of smoke and large amounts of sulphur dioxide (SO2) into the atmosphere. These have been transported by the prevailing winds towards Africa and the eastern Mediterranean. Andreas Richter, the scientist from the Institute of Environmental Physics at the University of Bremen who analysed the data, explains that: 'Even with its sporadic eruptions, Mount Etna is the largest source of sulphur dioxide in Europe, emitting more of the dangerous sulphur gas than all coal power plants and vehicles taken together.' Sulphur dioxide is one of the chief causes of acid rain, the phenomenon that reduces atmospheric visibility and causes damage to forests, soils, fish and other creatures, and human health. Despite the sharp reduction in concentration of SO2 recorded by the team in Germany, SO2 levels remain higher than normal at around 3.3 Dobson units (DUs), compared with a normal concentration of between 0 and 0.5 DUs. Although the evidence suggests that Mount Etna is beginning to settle down, other volcanoes around the world have also been very active. The Nyamuragira volcano in the Democratic Republic of Congo has been constantly emitting sulphur dioxide for weeks at levels comparable or higher than those observed near Etna. In South America, Ecuador's El Reventador volcano has released about four times more sulphur than Etna since its initial eruption on 3 November.