Very high concentrations of sulfur dioxide were measured at the eruption site today. Peak values were up to almost 2600 micrograms per cubic meter at Reyðarfjörður, which is by far the highest value ever recorded in Iceland. Consequently, a warning was issued for the town of Reyðarfjörður downwind, advising people to stay indoors as much as possible, especially children and the elderly. Healthy adults should not perform strenuous physical activities outdoors. The clouds of SO2 emitted by the Holohraun eruption may have been perceived by smell in Norway yesterday and have reached as far away as Northern Siberia at longitude 120 degrees East according to NASA surveillance. At times, local concentrations of SO2 are so high that they force an involuntary, temporary evacuation of the scientists from the base camp at Vadalda.