Reykjavik: Iceland's volcanic eruption has died down and is no longer spewing out ash, officials said on Wednesday as airlines began to get back to normal after cancelling about 1,000 flights in northern Europe.
The explosion of the Grimsvotn volcano on Saturday caused much less chaos than an eruption in 2010 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.
Hrafn Gudmundsson, a meteorologist at the Icelandic met office, told Reuters that mainly steam was coming from the crater, with no ash plume detected since 0300 GMT.
"There are indications that it's ceasing really," he said.
University of Iceland geophysicist Pall Einarsson said it was unlikely, though not impossible, that the volcano would begin disgorging significant amounts of ash again.
"At this stage we can at least hope for the worst to be over in terms of ash production," he said.
"At the moment there is practically no ash being produced and what little there is is being deposited on the glacier that is immediately around the crater."
After the eruption, the most powerful by Grimsvotn since 1873 and stronger than the one at 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, while four German airports - Bremen, Hamburg and Berlin's Tegel and Schoenefeld - closed on Wednesday only to be reopened hours later.
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 had 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.
US President Obama, who left Ireland early on Monday to travel to Britain to avoid being caught by the ash, is due to arrive in Poland later this week.
The ash cloud from Grimsvotn belched as high as 20 km into the sky after the eruption, but 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.
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.
Sources told Reuters 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 CEO 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 David Rothery expressed optimism this eruption was over, he added: "However, it will be back - next week, next year, or more likely next decade."