Ash generation and distribution from the April-May 2010 eruption of Eyjafjallajokull, Iceland

The 39-day long eruption at the summit of Eyjafjallajokull volcano in April-May 2010 was of modest size but ash was widely dispersed. By combining data from ground surveys and remote sensing we show that the erupted material was 4.8 +/- 1.2.10(11) kg (benmoreite and trachyte, dense rock equivalent volume 0.18 +/- 0.05 km(3)). About 20% was lava and water-transported tephra, 80% was airborne tephra (bulk volume 0.27 km(3)) transported by 3-10 km high plumes. The airborne tephra was mostly fine ash (diameter <1000 mu m). At least 7.10(10) kg (70 Tg) was very fine ash (<28 mu m), several times more than previously estimated via satellite retrievals. About 50% of the tephra fell in Iceland with the remainder carried towards south and east, detected over similar to 7 million km(2) in Europe and the North Atlantic. Of order 10(10) kg (2%) are considered to have been transported longer than 600-700 km with <10(8) kg (<0.02%) reaching mainland Europe.