Bang – Crash! How the Icelandic Volcano Caused Chaos

Ash plume erupting from Eyjafjallajökull on 17 April 2010.
Image by Boaworm, used under a CC-BY 3.0 license from Wikimedia commons.

On 14th April 2010, Eyjafjallajökull, a volcano in southern Iceland, began to erupt explosively. The eruption was not particularly powerful – ordinarily it would have only attracted the attention of those living nearby, along with a few volcanologists! However, on this occasion, the type of explosion combined with unusual weather conditions led to an unprecedented, total closure of the airspace over northern Europe and the North Atlantic. During the 6-day closure, 100,000 flights were cancelled and 10 million passengers left unable to travel.

The impact of the closure on commerce and leisure travel was global, dramatically highlighting the extent of modern reliance on air transport for goods and services. Also exposed were significant weaknesses in planning for a low-probability, high-impact event that was ‘known, but unprepared for’. So, why did Eyjafjallajökull take the aviation industry, governments and regulators by surprise?

The mid Atlantic Ridge as it crosses Iceland. Eyjafjallajökull is shown at the southern point.
Adapted from a public domain image by USGS.

The Hazard

Iceland sits astride the mid-Atlantic ridge and experiences a volcanic eruption roughly every five years – 75% of these are explosive. The explosions can be particularly violent when water mixes with the magma, creating very fine-grained ash.

Eyjafjallajökull – sat under an ice cap – had been rumbling since 1992. When it exploded in April 2010, ash, made fine by mixing with water, was ejected 10km up into the atmosphere where the wind – unusually – was blowing straight towards northwest Europe.


Ash and jet planes don’t mix! Ash damages the external surfaces of the plane, including the windscreen, and enters other systems such as air supplies for flight instruments. Worse still, modern jet engines work at temperatures hot enough to melt ash. The silica glass that results is deposited on fuel nozzles and turbine blades resulting in loss of thrust and potential engine failure. Terrifying incidents in which planes had descended 25,000 feet without power after passing through ash had been reported since the 1980’s.

The impact of volcanic ash on a jet engine.
Image copyright BBC News Online. used with permission

But Eyjafjallajökull also highlighted the extent of our reliance on air transport, and the complexity of the aviation industry and its governance. Air transport is estimated to carry up to a third of international trade, along with some 55% of all UK goods exported. Manufacturing industry relies on ‘just-in-time’ procurement methods where no spare stock is held and the goods are mainly high value to weight ratio. The completion of end products is reliant on rapid air transport of components, like microprocessors, in a complex supply chain that, if disrupted, rapidly incurs costs.

Less significant economically, but significant politically, 150,000 British tourists were stranded. What is more, the eruption exposed national governments’ lack of means to minimise the impact of lost air travel in a complex, fast time, private-sector dominated world.


Airborne ash detected outside Iceland, divided into three separate time intervals.
Image by Gudmundsson et al (2012)1, used under a CC BY-NC-ND 3.0 license from Nature Scientific Reports.

If the event was predictable and the hazard to planes known, why were we caught so short? Jet engine manufacturers knew the tolerances of their engines when exposed to ash – but didn’t share them. International guidance was simply to implement a complete no-fly zone when ash was detected, and governments and companies didn’t foresee the risk.

Air travel and volcanic ash clouds both cross national boundaries, but in 2010, integrated European air traffic management didn’t exist. Add to this a lack of clarity over ‘who had authority for what’, the range of competing perspectives and interests – from EU and national governments to regulators, insurers, plane and engine manufacturers, and scientists – and it is clear that national institutions were left without the means or ability to respond to the event.


The chaos that resulted led rapidly – and predictably – to media criticism of the response. Politicians were lobbied by various interest groups and were under pressure to show leadership (compounded in the UK by the upcoming May 2010 general election). There was little consensus as to the amount of ash, its direction or acceptable levels for safe flight; scientists were losing credibility over their approach to risk assessment, individual airlines began carrying out their own test flights and different EU countries were opening and closing their airspace based on their own interpretations of risk.

In the UK, the Government met in emergency mode (known as COBRA) to provide national co-ordination. COBRA exposed the difficulty in providing accurate scientific assessments of the risk, and for national governments dealing with an international problem. There was no doubt value in the UK Government creating the perception of ‘grip’, but tangible action was limited to the deployment of the Royal Navy to repatriate some (allegedly) vulnerable British tourists – little more than a token response to the criticism.

Nothing scary here! Synthetic Aperture Radar Image of Eyjafjallajökull on 15 April 2010.
Image by NASA is in the public domain.

The longer-term response is more impressive, however, with improvements in EU integration of air traffic management. In the UK, the event led to a review of the Government’s preparedness to deal with high impact, low probability risks; volcanic hazard was included in the National Risk Register; and additional Natural Environment Research Council [NERC] funding made available for further work on scenario modelling.

The potential for a volcanic eruption to impact air travel, and even health, in Europe was highlighted by this short-lived event. The vulnerability of a means of transport that is critical to a modern economy was clearly exposed by this ‘known but unprepared for’ risk. Had the eruption been more severe and persisted for longer, there was potential for Europe to be put back in recession.

There is evidence that the Icelandic ice caps are thinning2, which increases the potential for volcanicity, so these preparations may be tested more frequently in the future. Whether governments and businesses have fully learned the broader lessons relating to planning for things that might happen (as opposed to those that have), and are better prepared to assess the risk and respond, will remain to be seen!


1. Gudmundsson, M. T et al (2012), Ash generation and distribution from the April-May 2010 eruption of Eyjafjallajökull, Iceland. Scientific Reports 2: 572
2. Compton, K., Bennett, R. A. and Hreinsdóttir, S. (2015), Climate-driven vertical acceleration of Icelandic crust measured by continuous GPS geodesy. Geophys. Res. Lett., 42: 743–750. doi: 10.1002/2014GL062446.

Further Reading

Sammonds P, McGuire W and Edwards S (Eds) (2010). Volcanic hazard from Iceland: analysis and implications of the Eyjafjallajökull eruption. UCL Institute for Risk and Disaster Management

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