PARIS — Civil aviation authorities closed airspace and shut down airports in Britain, France, Scandinavia and other parts of Europe on Thursday as a high-altitude cloud of ash drifted south and east from an erupting volcano in Iceland.
The shutdown, among the most sweeping ever ordered in peacetime, forced the cancellation of thousands of flights and left airplanes stranded on the tarmac at some of the world’s busiest airports as the rolling cloud — made up of minute particles of silicate that can severely damage airplane engines — spread over Britain and toward continental Europe.
The Eyjafjallajokull volcano erupted Wednesday for the second time in a month, forcing evacuations and causing flooding about 75 miles east of Reykjavik. Matthew Watson, a specialist in the study of volcanic ash clouds from Bristol University in England, said the plume was “likely to end up over Belgium, Germany, the Lowlands — a good portion over Europe” — and was unlikely to disperse for 24 hours.
British aviation officials said the country’s airspace would remain closed at least until 7 a.m. local time Friday, meaning that only authorized emergency flights would be permitted. All of the roughly 6,000 scheduled flights that use British airspace each day would be affected, aviation experts said.
Deborah Seymour, a spokeswoman for Britain’s National Air Traffic Service, said the closure of the country’s airspace was the most extensive in recent memory. “It’s an extremely rare occurrence,” she said, noting that British airspace remained open even after the September 2001 terrorist attacks in the United States, with the exception of a no-fly zone over central London. She said there had been some brief airspace closings because of technical system failures in the past, but “nothing of this magnitude.”
Seven British Airways flights that departed Wednesday evening to Britain had to turn back after flying less than halfway, according to John Lampl, a British Airways spokesman in New York. They had departed from Chicago, San Francisco, Denver, Mexico City, Calgary, Vancouver and Las Vegas, Mr. Lampl said.
Eurocontrol, the agency in Brussels that is responsible for coordinating air traffic management across the region, said disruptions to air traffic could last another 48 hours, depending on weather conditions, and could extend deeper into continental Europe. On Thursday, roughly 20 percent to 25 percent of the 28,000 daily flights across Europe were canceled as a direct result of the ash plume, said Lucia Pasquini, a Eurocontrol spokeswoman.
As the ash cloud made its way high across the English Channel, France’s aviation authority said it was closing the main Paris airports, Charles de Gaulle and Orly, as of 11 p.m. About 20 other French airports began shutting down around 5 p.m.
Corinne Bokobza, a spokeswoman for the Paris airport operator, said the closings in Paris would affect no more than a dozen flights since the airports are normally closed from midnight to 5 a.m. She said it was not yet clear whether the airports would be allowed to reopen on Friday.
Even then, any resumption of flights would not be immediate, Mr. Lampl said. “For several days you’ll have crews and airplanes in the wrong places,” he said. “It will take a few days to sort it out.”
Oddly for many travelers, the closings were announced under clear blue skies, with the plume not visible from the ground.
The volcanic ash was reported to be drifting at 18,000 to 33,000 feet above the earth. At those altitudes, the cloud is directly in the way of commercial airliners, but not an immediate health threat to people on the ground, the International Volcanic Health Hazard Network, based in England, said on its Web site.
Major American carriers that fly to Britain were allowing their passengers to rebook flights without penalty on Thursday. United Airlines offered waivers on flights through Friday on its Web site.
American Airlines said that it was able to operate 15 flights into and out of London on Thursday morning before the airspace was closed around midday. “The flights encountered no ash,” said Tim Smith, an airline spokesman. The remaining 19 London flights on its schedule were canceled, as were two more bound for Manchester.
Continental canceled 32 flights, primarily those originating from its hub in Newark and a handful from its hub in Houston, according to Mary Clark, a spokeswoman for the airline. Anthony Black, a spokesman for Delta, said that it was waiting for additional information from Europe “to determine any additional adjustments.” Delta, through its Northwest subsidiary, has a European hub in the Netherlands, whose airspace closed at 6 p.m. Thursday.
German airspace remained open as of Thursday evening, though at the country’s busiest airport in Frankfurt, roughly 150 to 200 flights were canceled out of a normal daily total of about 1,400, said Thomas Über, a spokesman for the airport operator Fraport. Most were flights going to or arriving from Britain, Scandinavia and Iceland, he said.
The potential economic effect of the closings was “virtually impossible” to determine at this stage, said Peter Morris, chief economist at Ascend, an aviation consultancy in London
“A ballpark estimate would be that half a million to a million people’s travel will be disrupted in the U.K. over a couple of days, assuming things start to clear up soon,” he said. “For the long-haul players, especially those headed to the other side of the world, it’s a nightmare.”
Inside Terminal 4 at Heathrow, where flights leave London for Houston, New York and Paris, among many other destinations, all check-in counters were closed. Arrival and departure boards listed all flights as canceled. News of the impending closing seemed to have reached passengers before the shutdown, though, and the terminal was all but deserted. Airport staff in yellow slickers handed out fliers offering apologies and saying the closure was due to the “volcanic dust cloud from Iceland.”
Some of the few passengers at the terminal seemed stoic about their fate.
Jai Purohit, a manager from Leicester, England, who had planned fly to the United States to join his wife on vacation in Florida, said: “It’s very sad. I bought some nice presents for my wife and was looking forward to spending some time with her. She’s naturally upset, but there’s nothing we can do. It’s understandable.”
An American traveler, Anne Evans, who had arrived in London from San Francisco, said she was on the way to take up a voluntary teacher training position in Sri Lanka when she learned from television news that her connecting flight was canceled.
“I’m sort of in limbo,” she said. “They advised me to wait until 7 p.m. There’s nothing you can do. You can either smile or cry, and I decided to smile.”
Travelers on British Airways are only just recovering from a series of strikes by cabin staff.
Although volcanic ash clouds sometimes limit pilots’ visibility, their most serious safety threat to aircraft is the harm they can cause to engines in flight. In recent decades, more than 90 aircraft have suffered damage from volcanic plumes, according to the International Civil Aviation Authority, an arm of the United Nations.
Volcanic ash is made primarily of silicates, or glass fibers, which, once ingested into a jet engine can melt, causing the engine to flame out and stall.
It was impossible to predict how long the disruptions might last or the extent of the flight cancellations, since the volcano was still erupting, said Ms. Seymour at Britain’s National Air Traffic Service.
“We are completely and utterly hostage to weather conditions,” she said.
The perils of volcanic ash are well known to pilots and airline operators. After the 1982 eruption of Galunggung volcano in Indonesia, for example, a Boeing 747 flying to Perth, Australia, from Malaysia lost power in all four engines and descended from 36,000 feet to 12,500 feet before pilots could restart them and make an emergency landing in Jakarta, Indonesia.
In Iceland, hundreds of people fled their homes to avoid flooding after the eruption early on Wednesday melted the Eyjafjallajokull glacier. But Icelandic airports remained open because the wind was blowing the ash away.
The eruption, 10 times more powerful than another one nearby last month, showed no sign of abating after more than 24 hours of activity, a University of Iceland volcanologist, Armannn Hoskuldsson, told Reuters.
Hot fumes from the eruption melted vast amounts of ice on the glacier, Iceland’s fifth largest, but flood waters, which had caused damage to roads and bridges on Wednesday, were receding, Mr. Hoskuldsson said. Most of the 700 people who were evacuated from their homes on Wednesday were still huddled at Red Cross emergency centers set up nearby, an official told Reuters.