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Grimsv?tn eruption, Iceland
A new eruption began on Iceland on 21 May, from Grimsv?tn volcano. Volcanic ash is falling on Iceland and the Volcanic Ash Advisory Centre, London ( www.metoffice.gov.uk/aviation/vaac)/) has an advisory predicting an ash cloud over northern UK and Ireland from early Tuesday (24 May) morning (see image below).
For those in Iceland, please visit our Pamphlets page to download information on the health hazards of ash and preparedness for ashfall, in Icelandic.
For those concerned about potential ashfall across the UK or Europe, please read the following statement (below) regarding the hazard of the Grimsv?tn and Eyjafjallaj?kull ash.
Help the scientists: If you do experience ashfall and would like to help us to understand about the ash, please visit the BGS website to read information on how to collect a sample and send it to us. If you are in Iceland and have substantial ashfall, please follow the IVHHN guidelines on ash collection and send samples to Claire Horwell.
IVHHN Statement: Ash fallout from Icelandic eruptions across the United Kingdom and Europe
As we saw with the Eyjafjallaj?kull eruption of April-May 2010, and now the Grimsv?tn eruption of May 2011, explosive eruptions of Icelandic volcanoes can occasionally inject volcanic ash particles into the atmosphere under conditions where the windfields may then bring that ash across the United Kingdom and Europe. In April-May 2010, the Eyjafjallaj?kull eruption was unusually violent (probably because of the thick ice cap on the volcano, and the explosive interaction of molten rock with this ice), and produced an unusual quantity of fine to very fine ash, which was then transported across the UK and Europe at relatively low levels in the atmosphere (less than a few kilometres altitude), with well documented consequences for aviation. The current eruption of the Grimsv?tn volcano is likely to produce a far smaller proportion of fine ash; initial reports from Iceland suggest that less than ten percent of the ash is ?fine ash?, which is about half the value during the Eyjafjallaj?kull eruption.
In the early stages of the Grimsv?tn eruption, the ash layer was injected at a higher altitude in the atmosphere than in the 2010 eruption, but the ash level will typically descend to lower altitudes as the cloud is blown further away from the volcano. The coarser ash particles will probably fall out of the plume much closer to Iceland, and as a consequence there may be very little ash fallout across the UK when the ash plume passes over.
Our experience from last year?s Eyjafjallaj?kull eruption is that even in areas of the UK where the fine ash from the eruption fell out of the plume and was deposited on the ground, there were no unusual consequences: most of the ash particles were too coarse (20 ? 50 microns) and at too low a concentration to have any detectable impact on air quality. In fact, in most ?dust? samples which were collected at the time (whether on sticky tape, or on car windscreens, or at air sampling sites), most of the dust particles were not of volcanic ash at all, but a mixture of natural mineral grains and pollen grains, both of which are usually found in airborne dust.
Written by Prof. David Pyle, Oxford University, for IVHHN on 23 May 2011, updated 24 May 2011.
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A new eruption began on Iceland on 21 May, from Grimsv?tn volcano. Volcanic ash is falling on Iceland and the Volcanic Ash Advisory Centre, London ( www.metoffice.gov.uk/aviation/vaac)/) has an advisory predicting an ash cloud over northern UK and Ireland from early Tuesday (24 May) morning (see image below).
For those in Iceland, please visit our Pamphlets page to download information on the health hazards of ash and preparedness for ashfall, in Icelandic.
For those concerned about potential ashfall across the UK or Europe, please read the following statement (below) regarding the hazard of the Grimsv?tn and Eyjafjallaj?kull ash.
Help the scientists: If you do experience ashfall and would like to help us to understand about the ash, please visit the BGS website to read information on how to collect a sample and send it to us. If you are in Iceland and have substantial ashfall, please follow the IVHHN guidelines on ash collection and send samples to Claire Horwell.
IVHHN Statement: Ash fallout from Icelandic eruptions across the United Kingdom and Europe
As we saw with the Eyjafjallaj?kull eruption of April-May 2010, and now the Grimsv?tn eruption of May 2011, explosive eruptions of Icelandic volcanoes can occasionally inject volcanic ash particles into the atmosphere under conditions where the windfields may then bring that ash across the United Kingdom and Europe. In April-May 2010, the Eyjafjallaj?kull eruption was unusually violent (probably because of the thick ice cap on the volcano, and the explosive interaction of molten rock with this ice), and produced an unusual quantity of fine to very fine ash, which was then transported across the UK and Europe at relatively low levels in the atmosphere (less than a few kilometres altitude), with well documented consequences for aviation. The current eruption of the Grimsv?tn volcano is likely to produce a far smaller proportion of fine ash; initial reports from Iceland suggest that less than ten percent of the ash is ?fine ash?, which is about half the value during the Eyjafjallaj?kull eruption.
In the early stages of the Grimsv?tn eruption, the ash layer was injected at a higher altitude in the atmosphere than in the 2010 eruption, but the ash level will typically descend to lower altitudes as the cloud is blown further away from the volcano. The coarser ash particles will probably fall out of the plume much closer to Iceland, and as a consequence there may be very little ash fallout across the UK when the ash plume passes over.
Our experience from last year?s Eyjafjallaj?kull eruption is that even in areas of the UK where the fine ash from the eruption fell out of the plume and was deposited on the ground, there were no unusual consequences: most of the ash particles were too coarse (20 ? 50 microns) and at too low a concentration to have any detectable impact on air quality. In fact, in most ?dust? samples which were collected at the time (whether on sticky tape, or on car windscreens, or at air sampling sites), most of the dust particles were not of volcanic ash at all, but a mixture of natural mineral grains and pollen grains, both of which are usually found in airborne dust.
Written by Prof. David Pyle, Oxford University, for IVHHN on 23 May 2011, updated 24 May 2011.
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