Volcanic Ash clouds
Ash clouds occur where a violent explosive eruption ejects volcanic ash into the atmosphere. Bouyed up by the force of the eruption and the small size of particle the ash(< 2mm) may stay aloft for 10s to 1000s of kilometres from the vent. In some case volcanic ash can circulate the globe. Ash is composed of small shattered fragments of rock and volcanic glass particles. When gas or water vapour expands dramatically within the magma rocks are blown to pieces by the sudden expansion- an eruption.
Ashfall clouds can block out the sun, are often accompanied by a strong sulphurous smell and unlike snowfall does not melt away.Main problems are:
- Disruption to air travel, Volcanic ash is highly abrasive and will scour the windscren of and aircraft. Ash sucked into jet engine will remel and clog the engine causing engine failure.
- Roof collapse
- Poor visibility
- Acid coating on ash irritating lungs and eyes
- Contamination of water supplies
- Vegetation damage
- Increase chance of Lahar formation
Eyjafjallajokull Ashcloud 2010
In spring 2010 Eyjafjallajokull,avolcano in Iceland,began an eruption which would effect all of Europe. On April 14 an eruption under the crater glacier started , the heat from the eruption melted the ice which then entered the veent causing amore explosive eruptionThe resultant ash cloud was blown south wards towards Europe.UK Airspace was closed from 15-23rd April, 4-5 May and 16-17 May.