Britain could freeze in years of super-cold winters and miserable summers if the Bardarbunga volcano erupts, experts have warned
Image
© AP
Depending on the force of the explosion, minute particles thrust beyond the earth's atmosphere can trigger decades of chaotic weather patterns.

Tiny pieces of debris act as billions of shields reflecting the sun's light away from earth meaning winter temperatures could plunge lower than ever before while summer will be devoid of sunshine.The first effect could be a bitterly cold winter to arrive in weeks with thermometers plunging into minus figures and not rising long before next summer.

The Icelandic Met Office has this week warned of "strong indications of ongoing magma movement" around the volcano prompting them to raise the aviation warning to orange, the second highest and sparking fears the crater could blow at any moment.The region has also this week been hit by a magnitude-four earthquake - the strongest for almost 20 years, officials said.The British Met Office said the effects of an explosion on Britain's weather depends on the wind direction in the upper atmosphere. Spokeswoman Laura Young said: "If the upper winds are north-westerly it will have an effect on our weather."If the upper winds are westerly then it won't."

Historic volcanic eruptions have had devastating effects on the weather in surrounding areas which have lasted for years.In 1783 eastern regions of the United States recorded the lowest ever temperature after Iceland's Laki volcano erupted that year.As well as huge volumes of ash, the furious mountain also spat out large volumes of sulphur dioxide gas which added to the cooling effect.In Indonesia, the eruption of Mount Tambora in 1815 led to an unusually cold spring and summer the following year.The bizarre effect on the weather also ruined corn crops devastating farmers and leading to a food crisis.

Parts of Europe and America saw snow in June due to the eruption which also led to a shifting of the Atlantic sea ice. After Krakatau erupted in Indonesia in 1883 the world was hit by colder than average conditions for months although it is reported airborne particulate matter led to brilliant sunsets which were the subject of several late 19th-century paintings.

Experts put the phenomenon down to suspended dust and ash in the upper atmosphere and stratosphere blocking out the sunlight - the so called 'haze effect'.They also say sulphur released from the volcano mix with water vapour in the stratosphere to form clouds of sulphuric acid droplets, which take years to dissipate, lead to a reduction in global temperatures.

The 1980 eruption of Mount St Helens in Skamania County, Washington, United States, led to global temperatures dropping by 0.1C. Two years later the El Chichon volcano in Mexico spat much less debris into the sky but a greater amount of sulphurous gasses is thought to have triggered a global temperature drop of up to five times the St Helens effect.

Weathermen say the effect in the UK could be nothing short of catastrophic if an explosion is strong enough.Jonathan Powell, of Vantage Weather Services, said: "There is a definite potential knock-on effect and with an eruption looking imminent, this is fairly worrying.
"Particles can also be picked up by the jet stream ands spread globally, a large amount can have a significant effect on the weather, the first could be an exceptionally cold winter this year."But the effects can last for many years, even decades."

However David Rothery, professor of planetary geosciences at the Open University, sought to allay fears over the threat posed by Bardarbunga.He said: "We would need to see a very big explosion to get enough ash to affect the temperature on the ground, we are talking about climate more than anything, what happens is it gets cooler because the sunlight doesn't get through."We don't even know if the eruption will be explosive, it might just be lava and a little bit of ash thrown into the sky."You can also see gasses like sulphur dioxide which can cause respiratory problems, but it is almost certain we are not looking at anything of that magnitude."

Dr Dave McGarvie, senior lecturer in volcanology at the Open University, added: "We've known for some time that Bardarbunga was going to do something - we just didn't know what.
"Now she has stirred, she is giving us clues about what she is going to do."The clues from the pattern of earthquakes show that seismic energy is being expended in two main clusters - one to the North East on the glacier margin, and one to the East under the ice. Adding in the clues from the pattern of earth movements indicates that magma is moving towards the surface, and if it gets there it will erupt."Current indications are that if an eruption happens it will produce modest amounts of denser ash and only cause local disruption to air travel.
"But we know so little about this volcano that she could surprise us."

Dr Nicolas Bellouin, an expert on atmospheric dust clouds at the University of Reading, said: "The current cold snap many of us are experiencing in the UK is due to the fact that at the moment the wind is coming from the north - putting Britain directly in the firing line of any volcanic eruption from Iceland, if it happens in the next few days.

"Volcanic ash is made of tiny pieces of sand and minerals, blasted out from an erupting volcano, which are then suspended in the atmosphere and transported by winds.

"Where the ash goes is dependent on the direction of the wind. If winds continue to blow from Iceland to the UK, as they are at the moment, ash from an eruption will be transported to the UK and northern Europe."