Airline passengers are facing potential travel chaos amid fears that ash from a newly erupting Icelandic volcano could reach Britain on Tuesday.
Forecasters said the plume from the Grimsvotn volcano could be blown to northern Scotland, and the rest of Britain by Thursday.
If concentrations are high, no-fly zones could be imposed over the UK by the Civil Aviation Authority.
Iceland’s airports were closed and domestic flights cancelled as a spectacular 12-mile high mushroom cloud of ash, steam and smoke filled the sky.
Authorities in the UK initially said there was little chance of disruption to airspace. But as a low pressure weather system moves into Europe, there are fears north-westerly winds capable of blowing ash towards Britain will pick up.
Airlines were told to brace for the possible further spread of ash later in the week. A spokesman for the Met Office, which runs the UK’s Volcanic Ash Advisory Centres, said: “It depends on how long the volcano continues to erupt and the weather patterns that develop.
“If it continues to erupt, there is a risk of volcanic ash over Britain later in the week.”
The CAA said lessons had been learned from last year when fine ash from another Icelandic volcano, Eyjafjallajškull, shut European airspace for a week. The no-fly zone - imposed after fears that ash could clog up aircraft engines - cost up to £2-billion and led to disruption for ten million passengers.
Airlines claimed the rules were too strict and their planes could cope with low concentrations of fine grained dust.
But a scientific study published last month by experts at the University of Iceland concluded that the levels of ash were high enough to damage engines and cause a disaster.
The new warning assumes the volcano will continue to spew ash at the same rate and there is no change in forecasts over a period of five days.
Although the latest eruption is far larger, volcano experts say its ash is far heavier and will fall to the ground more quickly.
University of Iceland geophysicist Magnus Tumi Gudmundsson said: “There is a very large area in south-east Iceland where there is almost total darkness and heavy fall of ash. But it is not spreading nearly as much. The winds are not as strong as they were in Eyjafjallajškull.”
The ash on Monday covered buildings, cars and fields in a thick layer of grey soot. Civil protection workers urged residents to wear masks and stay indoors. Keflavik airport, the country’s main hub, was closed.
The Grimsvotn volcano, which lies under the uninhabited Vatnajokull glacier about 120 miles east of the capital, Reykjavik, began erupting on Saturday for the first time since 2004.
When it last erupted in 2004, transatlantic flights were re-routed but no airports were shut.
A spokesman for the CAA said: “What matters most is the concentration. If the ash is dense then we will have to restrict flights. But the work that has been done in the last year means we known engines can cope with certain concentrations of ash. Airlines can consider flying in lower concentrations if they can provide a safety report.”
Dr Dave McGarvie, Volcanologist at The Open University, said: “If the eruption continues with its current intensity and we get unfavourable winds, we could see ash over the UK. “
“But the past two eruptions in 1998 and 2004 from this volcano did not affect UK air travel. The amount of ash reaching the UK is likely to be less than in the 2010 Eyjafjallajškull eruption. “
“In addition, the experience gained from the 2010 eruption Ð especially by the Met Office, the airline industry, and the engine manufacturers - should mean less disruption to travellers.”
British Airways said on Sunday night said it was monitoring the situation closely but did not expect it to have any effect on flights over the next 24 hours. - Daily Mail