REUTERS STOCKHOLM/REYKJAVIK ICELAND’S volcanic eruption has died down and is no longer spewing out ash, officials said on Wednesday and airlines began to get back to normal after cancelling about 1,000 flights in northern Europe.

The explosion on Saturday of the Grimsvotn volcano caused much less chaos than an eruption last year at another Icelandic volcano thanks to new rules for airlines, but the incident showed problems remain with the regulations.

Budget airline Ryanair was vocal in its criticism.

“There are indications that it’s ceasing really,” said Hrafn Gudmundsson, a meteorologist at the Icelandic met office.

He said that mainly steam was coming from the crater, with no ash plume detected since 11 pm EDT.

“I am cautiously optimistic the main ash-producing phase of this eruption has now ceased,” Dr David Rothery of Britain’s Open University Volcano Dynamics Group said in emailed comments.

After the eruption, the most powerful by Grimsvotn since 1873 and stronger than Eyjafjallajokull that caused air traffic chaos last year, a massive plume of ash spread across northern Europe.

Flights in Scotland and northern England were cancelled on Tuesday.

A cloud of volcanic ash blew further north and east on Wednesday afternoon, allowing German air traffic to resume as experts said the eruption appeared be winding down.

Dutch airline KLM resumed flights to affected destinations after a brief break.

European air traffic agency Eurocontrol said 500 flights had been affected on Tuesday and a spokeswoman said Eurocontrol expected 700 flights to be cancelled over Germany.

Eurocontrol said the ash could would drift to Poland, but a Polish air traffic control official said no traffic limitations were due.

The ash cloud from Grimsvotn belched as high as 20 km (12 miles) into the sky after the eruption, but it did not trigger the kind of travel chaos caused by Eyjafjallajokull when more than 10 million people were hit by a six-day European airspace shutdown.

That cost airlines $1.7 billion.

However, Grimsvotn’s eruption did expose disarray among the authorities who decide on aviation safety as they try to apply new rules to avoid another mass closure of European airspace.

New procedures put the onus on airlines to make judgments on whether it is safe to fly through ash, in coordination with the forecasting authorities, particularly the Volcanic Ash Advisory Centre at the British Met Office, and civil aviation bodies.

Highlighting problems, sources told Reuters that a British research plane designed to sample ash remained grounded for a second day in a wrangle over its deployment.

Ryanair on Tuesday said it had safely sent two planes into what authorities had deemed high ash zones over Scotland, and criticised “bureaucratic incompetence.” International Airlines Group Willie Walsh also said his company had flown a plane into an ash zone.

“The simple answer is we found nothing,” he told BBC radio.

He called for the British authorities to use multiple sources of data when deciding on how to react to ash problems.

“The potential for a patchwork of inconsistent state decisions on airspace management still exists,” IATA Director General Giovanni Bisignani said in a statement, calling on Tuesday for more coordination.

Grimsvotn is Iceland’s most active volcano.

Though the Open University’s Rothery expressed optimism this eruption was over, he added: “However, it will be back - next week, next year, or more likely next decade.”