Threat of eruptions is far from dormant

The idea of volcanic ash closing Edinburgh airport may have sounded like a joke to most of us, but yesterday's events were not as unpredictable as you might think, says environment reporter Chris Marshall

THE cloud of ash which grounded flights across Britain yesterday may have been the closest most of us have ever come to feeling the destructive power of the volcano.

Their awe-inspiring eruptions do seem like the kind of thing that happens only in far off lands, ancient history books and adventure films.

But they do happen, albeit usually on a smaller scale, on a daily basis in European holiday destinations.

There had been indications before yesterday that the volcano under the Eyjafjallajoekull glacier in Iceland was about to explode again.

But the eruption that came, throwing volcanic ash up to 7km into the atmosphere and closing down air traffic across northern Europe, was ten times more powerful than another nearby last month.

Another such eruption is very possible elsewhere in Europe at almost any time, with no guarantees we would escape the chaos in Scotland.

There are a handful of active volcanos in Europe – the last eruption in Scotland was at least 55 million years ago – with most sited in or near popular holiday spots.

Mount Etna on Sicily and Mount Stromboli in the nearby Aeolian Islands remain Europe's most active volcanoes.

According to experts, Stromboli is almost continually erupting, while Etna erupts every year or so. There are also a number of active volcanoes in Iceland, Turkey and the Greek islands.

It is Vesuvius and the lesser-known Campi Flegrei, both near Naples, however, which continue to give scientists most cause for concern.

Vesuvius is said to have erupted around 50 times, the last time being 1944. Its proximity to Naples, a city of around a million people, means it is constantly being monitored by scientists.

Dr Andrew Bell, a volcanologist at Edinburgh University's School of Geophysics, says Vesuvius could erupt at any time.

"Vesuvius last erupted in 1944, during the Second World War. There are no obvious signs that it is about to do so again, but I wouldn't be surprised if it erupted in the near future."

Our own landscape in Edinburgh, and elsewhere in Scotland, was shaped by volcanic activity, but that is now part of ancient history. Arthur's Seat, an extinct volcano, has not erupted for 200 million years, while peaks in Skye and Rum have not erupted for between 55 million and 60 million years.

The immediate concern for us is the risk to aeroplanes and the disruption caused by cancellations caused by the eruption in Iceland. There is good reason to be cautious when it comes to flights. Four engines of a British Airways jumbo shut down in 1982 after the plane flew through a plume of volcanic ash.

Another concern might be for effects of the ash which could drift down on to our homes and gardens.

The Scottish rugby team are among those to have encountered ill effects in the past. Following the eruption of New Zealand's Mount Ruapehu in 1996, the touring Scottish players were given advice including not to wash their hair in case the shampoo reacted with the volcanic ash.

During a game against Bay of Plenty, Scotland player Derek Stark became unwell after inhaling too much ash.

Experts, though, are convinced there is no reason to fear any effects on our health. Professor Malcolm Green, a spokesman for the British Lung Foundation, says: "The ash cloud that is presently over Scotland is unlikely to pose a health hazard to our lungs. However, we would recommend anyone with a lung condition to carry medication as a precaution."

Dr Dougal Jerram, of Durham University's Department of Earth Sciences, says a massive Icelandic eruption in the 18th century resulted in thousands of deaths, but he assured people there was no current risk to health.

"The high altitude of the current plume above the UK means that it is air traffic and not humans on the ground that will suffer," he says.

"One of the most influential ever eruptions was the 1783-1784 event at Laki in Iceland when an estimated 120 million tons of sulphur dioxide were emitted.

"This resulted in many thousands of deaths throughout 1783 and the winter of 1784."

One positive aspect of the current disruption is that scientists are being afforded a relatively rare opportunity to study a volcano in action.

Edinburgh University's Dr Bell adds: "It is exciting to see one of these events happen and it gives us lots of information about why they happen."