Researchers at the University of Leeds in Britain and other institutions used computer simulations to investigating the likely atmospheric effects if a "flood lava" eruption were to take place in Iceland today.
Flood lava eruptions, which stand out for the sheer quantities of lava and hazardous gases they release, have occurred in Iceland four times in roughly the past thousand years, records indicate.
The most recent such eruption was that of the Laki volcano in 1783-84, which generated a sulfuric acid haze that dispersed over Iceland, France, England, the Netherlands, Sweden, Italy and other countries, killing a fifth of Iceland's population and three-quarters of the island's livestock.
Laki blasted 122 million tons of sulfur dioxide into the atmosphere, 50 to 100 times more per day than Iceland's Eyjafjallajokull volcano in 2010 that shut down European air space for a week.
"It's known that flying through a volcanic ash cloud can damage aircraft," Leeds researcher Anja Schmidt said.
"In the case of a Laki-type eruption, high sulfur dioxide and sulfuric acid concentrations will have to be considered as an additional hazard."
Schmidt presented results from the study in Iceland Monday at the Chapman Conference on Volcanism and the Atmosphere, a meeting sponsored by the American Geophysical Union.