As the Eyjafjallajökull volcano in Iceland erupted, weather conditions meant that the volcanic ash covered a large area of Europe, causing widespread disruption to aviation. The Met Office had a key role in accurately predicting the spread of the ash and advising the aviation industry.
In our role as a Volcanic Ash Advisory Centre (VAAC), we're responsible for monitoring and reporting the spread of volcanic ash over the UK, Iceland and the north-eastern part of the North Atlantic Ocean.
When low-level eruptions from the Eyjafjallajökull volcano in Iceland increased significantly on 14 April, we advised the Civil Aviation Authority (CAA) and National Air Traffic Services (NATS) where the ash would be every six hours.
The two agencies have responsibility for safety within UK airspace and decide whether the skies above the country are open or closed. Airspace was closed on 15 April which meant that many people across Europe had their travel plans disrupted.
Volcanic ash can have a major impact on aircraft, potentially causing engines to fail. The International Civil Aviation Organisation (ICAO) along with the CAA and aircraft manufacturers set safety thresholds for flying planes through volcanic ash. Our forecasts of ash plume trajectories are based on these thresholds.
As a Volcanic Ash Advisory Centre, we're very proud to provide advice to inform critical safety decisions. Our VAAC is an operational service, on watch around the clock, so as volcanic activity occurs and the weather changes we can provide timely guidance.
Our advice and hard work around the Eyjafjallajökull eruption was recognised as exemplary at the highest levels of Government and by the agencies we supported during the eruption.
|15 April||Met Office observers at Lerwick, Shetland Islands, report a reduction in visibility and a yellowish hue in the sky.UK airspace closed by the CAA and NATS.|
|17 April||Volcano continues to erupt. Many confirmed reports of dust deposits on cars across the bulk of Britain.|
|20 April||ICAO issues guidance that no aircraft should fly through volcanic ash.|
|23 April||Met Office forecasts change to weather patterns, causing ash to move away from the UK.|
|24 April||Restrictions on flights at Reykjavik and Keflavik, Iceland, due to the ash.|
|25 April||Slow decline in volcanic activity.|
|26 April||Airlines instructed by regulators to conduct a risk assessment before flying and engine inspections before and after each flight.|
|2 May||Eruption increases in intensity with the plume spreading southeastwards, away from Iceland.|
|5 May||Plume moves southwards to northern and western parts of the British Isles.|
|9 May||Aircraft report an ash cloud near the Pyrenees around 35,000 ft. Dense areas of ash move across parts of France and Italy.|
|12 May||Volcano continues to erupt. Lightning first detected in the plume.|
|17 May||New safety thresholds set by the CAA, based on information from engine manufacturers and airlines.Ash cloud visible in the skies above northern England.|
|22 May||Eruption decreases in intensity. Light winds over Iceland keep the plume close to the crater.|
|23 May||Volcano continues to emit a plume of steam but no ash.|
|25 May||Eruption remains at rest.|
The effect of volcanoes on our climate has led some to doubt the human impact on climate change. For example, it's been suggested that volcanoes put out more carbon dioxide (CO2) than human activity, but this is not the case.
In an average year, volcanoes put out an estimated 100-130 million tonnes of CO2 globally. Estimates suggest human activity puts out more than 200 times as much - about 26,000 million tonnes of CO2 per year, magnifying the greenhouse effect and causing our climate to change.
Last updated: 19 December 2011