Iceland Ash Did Pose Hazard

Nanoscale scrutiny of ash that spewed from an Icelandic volcano last year reveals that the tiny particles were uncommonly sharp and abrasive—and likely would have spelled trouble for aircraft in their path (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1015053108). Aviation officials in Europe “were right to close the airspace when they did,” says study leader Susan L. S. Stipp, a geochemist at the University of Copenhagen. Her colleagues Sigurdur R. Gíslason and Helgi A. Alfredsson from the University of Iceland collected ash about 35 miles from the crater as the Eyjafjallajökull volcano was erupting. A combination of techniques, including scanning electron microscopy, revealed that ash from the early stages of the explosive eruption was exceptionally fine and sharp and remained so even after being stirred in water in the lab for two weeks to simulate exposure to rain or fog. Stipp notes that abrasiveness isn’t the only potential problem; the small particle size makes it easier for ash to melt and potentially clog parts of jet engines. The team hopes their protocol for characterizing ash will aid risk assessment during future eruptions.