European authorities were right to shut down air traffic over the past week to avert any risk of disaster if planes flew through thick clouds of volcanic dust from Iceland, an international volcano expert said on Wednesday.
Henri Goudru, a United Nations scientific adviser with 40 years of experience in studying volcanic eruptions, told a news conference there had never been any serious study of the effect of such dust on jet engines.
"In the absence of reliable facts, the only thing to do was to stop aircraft from flying, given the risk to planes of suffering serious engine damage, perhaps crashing," said Goudru, French president of the European Volcanological Society.
"This was not an over-reaction. We simply do not know enough about these clouds and what can happen to planes flying into them," he said, speaking as Iceland's Eyjafjallajokull began spewing less ash and European skies reopened to air traffic.
Some politicians and commentators across Europe, as well as airlines, have suggested authorities acted too hastily in grounding flights last Thursday as the plume from the volcano spread across large areas of the continent.
The global airlines body IATA says the closure had cost its members $1.7 billion by Tuesday, while tens of thousands of travellers were left stranded far from home.
"But imagine if nothing had been done and we'd had a crash with serious loss of life," said spokeswomen Brigitte Leoni of the U.N.'s disaster reduction agency ISDR, which Goudru advises. "What would people have said then?"
Goudru, also president of the International Commission on Mitigation of Volcanic Disasters, said a proper study of the problem posed for aircraft by volcanoes should be carried out by aviation engineers, meteorologists and geophysicists.
"It would obviously be vital for future events of this type if we had answers to the questions that have been posed this time," he said.
The expert, who has observed volcanoes around the world, said the next eruption by Vesuvius, at the centre of a densely populated area on the Bay of Naples in Italy, could also pose problems to aviation beyond the immediate region.
The volcano, which destroyed the Roman city of Pompeii in AD 79 and is regarded as one of the world's most dangerous, last burst into life with force with a huge explosion in 1944 and specialists say it is likely to erupt again soon.
Although it has no glacier covering like its cousin in Iceland, its explosive nature sends clouds much higher and it could have a similar effect on aviation in at least southern and south-eastern Europe, Goudru said.
Specialist scientists and other experts would be meeting in Tenerife in Spain's Canary Islands from May 30 to June 6 at a meeting of the International Association of Volcanologists at which these issues would be discussed, he said.
