When will Iceland's volcano stop erupting?

ENVIRONMENT - Air travel in Europe has practically ground to an halt as ash and chemicals from an erupting volcano in Iceland makes air travel very dangerous. The amount of ash being spewed into the jet stream is such that most of northern Europe and parts of southern Europe have cancelled most of their air flights. Even transatlantic flights from Canada and the USA are being cancelled.

But the volcano in question (Eylafjallajökull) in Iceland just keeps on erupting. According to scientists there's no limit for how long it could keep erupting.

"So far its only been erupting for a bit over a month, but it could be years or decades before it either slows down and quiets completely," says one scientist/tourist in Iceland, there to enjoy the spectacle.

If that were true and the eruptions became a constant fixture it could spell disaster for Europe's aeroplane and tourism industries. It also is a danger for people with respiratory problems, who are currently being told to stay indoors.

When Mount Pintubo erupted in June 1991 the aerosols in the ash resulted in a global drop in temperatures by 0.4 degree C (0.9 degree F) and created a sulfuric haze that circled the globe for a period of a year. The eruptions only lasted 2 weeks but the effects were long lasting.

If Eylafjallajökull keeps erupting it could cause severe havoc to the global economy. Hypothetically an ash cloud that extends across Europe, Russia, Asia and eventually North America as it circles the globe could wreak any number of troubles to local economies that rely on air travel, tourism, warm temperatures, food imports and even military aircraft. Already economists are predicting billions of dollars in daily economic losses due to the disruption the volcanic ash is causing.

Eylafjallajökull is situated on the Mid-Atlantic ridge, a highly unstable volcanic region. Iceland itself has had constant eruptions for thousands of years, but this is the biggest one in recent history.

A similar eruption in 1783 of the Laki volcano in Iceland was recorded by Benjamin Franklin (then the American Ambassador to France) in which he records winter weather that lasted well into 1784, with the "effect of heating the Earth was exceedingly diminished. Hence the surface was early frozen. Hence the first snows remained on it unmelted. Hence the air was more chilled. Hence perhaps the winter of 1783-84 was more severe than any that had happened for many years."