Shortly after the Eyjafjallajökull volcano began erupting in Iceland last year, authorities in Europe and in other areas of the globe decided to shut down major airports, causing millions of euros in economic damages to numerous countries. An analysis of the ash released shows this was the right thing to do.
Scientists have recently finished conducting the most extensive and thorough investigation on the properties of the ash particles Eyjafjallajökull began releasing in April 2010. They found that the ash was extremely sharp and abrasive, which made it extremely dangerous for airplanes.
In other words, if the particles made their way into airplane engines, it could have caused a lot of damage during the flight, and conceivably lead to the crash of several flights. Therefore, closing down the airports was the best thing to do under the circumstances.
Geoscientists at the University of Copenhagen, led by expert Susan Stipp, were immediately on site as the volcano began erupting, and were the last to depart when meltwater caused by the lava flows washed away the roads around the mountain.
“Aviation authorities made the right decision,” team leader Susan Stipp explains. She conducted the work together with University of Iceland volcanologists Sigurdur Gíslason and Helgi Alfredsson.
The latter collected ash samples at the beginning of the eruption, and then again 12 days later. The ash was sent to Stipp's lab. Experts here conducted an extensive battery of tests on the particles, and details of the work appear in the April 25 issue of Proceedings of the National Academy of Sciences (PNAS).
One of the first things that caught investigators' eyes was the fact that the ash was very sharp. “The particles remain extremely sharp even after they’ve been grinding against each other” in a water tank for days, Stipp and her team says.
The work also revealed that ash produced at the start of the eruption was more powdery, smaller and a lot sharper than ash produced later on. A significant proportion was also found exhibiting the tendency to clump together around larger particles, which further increased breathing hazard to humans.
The implication of this is that more particles were spread at ground level than originally thought. The ash aggregates tended to break apart upon impact, spreading the powder over significant areas, Wired reports.
Test batteries such as this one could in the future be applied to other volcanic eruptions as well, Stipp says. This would enable scientists to gain a better understanding of the magnitude of the disaster they are facing, while the crisis is still ongoing.