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

The 39-day long eruption at the summit of Eyjafjallajökull 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 µm). At least 7·10(10) kg (70 Tg) was very fine ash (<28 µm), 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 ~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.