Irish Transport Minister Noel Dempsey said Tuesday's closure of Irish airspace "emphasizes the need for a strong European response and action plan to deal with this situation as it continues to evolve."

Iceland's Institute of Earth Sciences said Eyjafjallajokul - which erupted April 13 after a 177-year slumber - has experienced increased seismic activity since Sunday and its ash plume has risen to nearly 5.5 kilometers (18,000 feet) in altitude. The last time it erupted, in 1821, its emissions ebbed and flowed for two years.

At Dublin Airport, passengers said they doubted whether aviation chieftains could effectively cork the Iceland ash threat soon. Some turned their anger on Irish airlines for allegedly taking advantage of their misfortunes to gouge them on emergency-rebooked flights.

"We only got married on Saturday and a wedding is a lot of stress, so this was the last thing we needed," said Maria Colgan, standing beside her husband Brian Halligan after they sped to Dublin Airport and paid euro600 ($790) to catch the last Aer Lingus flight Monday out of Dublin to London.

The couple, both 30, felt they had no choice but to shell out because their honeymoon in Barbados required them to make a Tuesday connection in London.

"The ash isn't our fault. Aer Lingus could work with people like us, but they aren't interested, charging us full whack for flights to London," she said.

But most passengers camped out Tuesday during the shutdown appeared resigned to a dawning reality of uncertain air bookings. Many applauded the authorities' more selective shutdown Tuesday as a sign of improving systems and literally applauded as the Dublin departures terminals began listing takeoff times again.

"Ireland's an island. We're kind of stuck with air travel, for better or worse," said Elaine McDermott, 23, who lost her early flight to Paris to attend a college friend's wedding but found herself boarding a replacement service eight hours later.

"I'll make it to the church on time," she said with a relieved ere could be any real risk to the operation of an aircraft."

The Irish Aviation Authority said the risk of further shutdowns before midday Wednesday was "minimal."