It's been a month now, and Iceland's volcano shows no sign it will stop belching ash across Europe anytime soon. The rolling eruptions threaten more havoc for summer vacation plans and higher costs for struggling airlines.

Although the global disruption of last month's massive eruption has faded, smaller ash plumes snarled air services intermittently over the last week all the way to Turkey - more than 4,100 kilometers from the Eyjafjallajokul (pronounced ay-yah-FYAH-lah-yer-kuhl) volcano.

Air-control authorities and geologists agree that the continent must brace indefinitely for rapid shutdowns of air services as computerized 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 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 travelers 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. Two hours of jet fuel to divert to another airport can cost $5,000 to $10,000.

This weekend, Lufthansa couldn't land in Munich so it diverted planes to other German airports and bused passengers the rest of the way.

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," Barrera said.

Irish tourism centers dependent on Europeans and Americans arriving by air say their summer will be bleak if the volcano doesn't stop. Ireland's government has called in tourism industry officials emphasizing they must woo more Irish to compensate for the missing foreigners.

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," said Debbie Walsh, manager of a heritage museum.