Europe should brace itself for a summer of sudden flight disruptions caused by the Icelandic volcano, experts have warned.
Air-control authorities and geologists agree there are likely to be more cancellations to come as computerised projections try to pinpoint where the ash clouds will float next at the whim of shifting winds.
"We do not pretend to be psychics," said Einar Kjartansson, a geophysicist at the Icelandic Meteorological Office, who often has been asked to guess the volcano's next move since it began spitting lava and ash on March 20.
Huge volumes of ash, which can clog jet engines, forced most of northern Europe to shut its air services April 15-20, grounding an estimated 10 million travellers worldwide.
Since then the ash plume has thinned and spread out, shifting shape by the hour, rising into North Atlantic air routes and imposing awkward detours on hundreds of trans-Atlantic flights daily.
The costs to airlines associated with an ash cloud can add up quickly. Consider that two hours of jet fuel to divert to another airport can cost up to £7,000 depending on the size of aircraft involved.
Last weekend, Lufthansa could not land in Munich so diverted planes to other German airports and bussed passengers the rest of the way.
A Lufthansa spokesman said it had not yet calculated the extra costs of the sporadic diversions and grounding of aircraft over the past week.
Dozens of European airlines have suffered similarly and are already lobbying their national governments to help foot the bill, which includes paying the hotel and food bills of stranded customers.
Jose Luis Barrera, deputy president of Spain's College of Geologists, said Europe should get ready for ash-covered inconvenience at least through the summer - and perhaps longer. He noted that the volcano's last eruption ran from 1821 to 1823.
"We're going to have to learn to live with the volcano," he said. "Just as in California, people learn to live with the earthquake that may be waiting for them. ... This is the same. Preventive measures will have to be taken for if and when the mass of ash gets worse."
Irish tourism centres dependent on Europeans and Americans arriving by air say their summer will be bleak if the volcano does not stop. Ireland's government has called in tourism industry officials emphasising they must woo more Irish to compensate for the missing foreigners.
"Pre-volcano we were having a great year. Then all hell broke loose, thanks to your man (the volcano)," said Debbie Walsh, manager of a heritage museum in the County Cork port of Cobh.
She said this summer the key to financial survival would be the approximately 50 cruise liners expected to disgorge tourists in Cobh. "We're lucky in that we can fall back on the cruise liners. Nothing is going to stop them from coming in."
Lufthansa, one of Europe's most financially secure airlines, said its bookings are on target with what they would expect this time of year. But analysts warned that most carriers are on shakier financial ground, depend on summer holidaymakers for the bulk of their profits - and are particularly vulnerable to a drop-off in bookings now.
Airline, business and tourism leaders have also increasingly questioned Europe's competence to measure the true threat.
Criticism has been sharpest in Ireland and Britain, heavily dependent on air links for their economic health.