Thursday, February 28, 2013

[Geology2] Ash from Icelandic volcano vastly underestimated



Ash from Icelandic volcano vastly underestimated

26 February 2013, by Alex Peel

The Icelandic volcano that wreaked havoc on Europe's airways in 2010 released 100 times more ash than originally thought, scientists say.

Eyjafjallajokull volcano

The study, published in The Journal of Geophysical Research, could allow us to forecast ash clouds from future eruptions more accurately, paving the way for improvements in the management of airspace.

'Before now, people have estimated the amount of ash in an eruption from the height of the plume, but this approach is only reliable in still air,' explains Dr. Mark Woodhouse of the University of Bristol, the study's lead author.

'We know that this eruption was very strongly affected by the wind,' he adds.

'We've found that, for small explosive eruptions, like the one at the Eyjafjallajokull volcano in 2010, the wind can have a very significant effect on the plume of ash.'

The April 2010 eruption released a cloud of ash that rapidly spread across Europe, grounding planes and cancelling holiday plans for thousands looking to take advantage of the Easter break.

'This study represents an important development in our modelling of volcanic plumes'
Dr. Mark Woodhouse,
University of Bristol

Forecasters used data from the Met Office, the expertise of volcanologists and observations from NERC's Dornier 228 aircraft to predict the path and impact of the cloud.

At the time, there was no reliable model for predicting how much ash the volcano was emitting.

Now, mathematicians and Earth scientists have worked closely together to simulate the effect of wind on explosive eruptions.

They found that strong winds prevented the plume from reaching as high as it would in a still environment.

This means estimations of ash quantities that rely on plume-height measurements alone could be dramatically undershooting the real figure.

Woodhouse hopes that, in providing a new model to take account of the wind, their work will leave us better prepared for future eruptions of this kind.

'This study represents an important development in our modelling of volcanic plumes,' he said. 'The results can complement the state-of-the-art forecasting tools used to predict the spreading of ash during volcanic crises.'

The research was part of a Natural Environment Research Council-funded consortium, working to learn the lessons of the 2010 eruption to better prepare the UK for future volcanic crises.

Woodhouse MJ, Hogg AJ, Phillips JC, Sparks RSJ, Interaction between volcanic plumes and wind during the 2010 Eyjafjallajokull eruption, Iceland, 2013, Journal of Geophysical Research, doi: 10.1029/2012JB009592

http://planetearth.nerc.ac.uk/news/story.aspx?id=1386&cookieConsent=A
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