Eyjafjallajokull 2010: chronology of magmatic processes and their linkage to unrest signals and eruption behaviour

The eruption of Eyjafjallajokull volcano in 2010 caused widespread disruption, travel chaos and economic damage across Europe, closing airports, stranding tourists and halting air freight. At least 13 major travel operators went bust in 2010, with the eruption being a significant contributing factor.

Whilst many studies focus on the behaviour of ash when injected into the atmosphere, this project is concerned with the magma itself. The Eyjafjallajokull eruption followed over a decade of periodic unrest, with suspected magma movements beneath the volcano in 1994, 1996 and 1999. When it did erupt, the volcano produced a magma that was clearly a mixture of three components, an evolved, sticky magma and two different hot, basaltic magmas, which interacted with and heated up the evolved component so that it could be erupted.

Crystals in the magma record the mixing event, by growing zones with different compositions. If the crystals sit in a hot magma chamber, they gradually reset towards a uniform composition. By looking at how far this resetting process has gone, we can determine how long it has been since the zones formed, and by inference, since the magmas mixed. Our initial work looking at these samples has shown that there are multiple mixing events, occurring up to 18 months before the eruption itself occurred. A major mixing event seen in many crystals correlates with the start of the summit eruption, and it is reasonable to expect that new mixing events - representing fresh magma input - would have a strong impact on the state of the eruption.

This project will have two research strands, operating at Edinburgh and Leeds, with involvement of the British Geological Survey as a key stakeholder. The role of Edinburgh is to refine what we know about the character of the products, to identify the three mixing components and their properties such as temperature and water content. The role of Leeds is to determine the times at which the magmas have mixed before they erupt, and to then use this to show the series of events that happened in the magma chamber beneath the volcano, both before, and during, the eruption.

With this data, we will be able to "date" the mixing events recorded in crystals from throughout the eruption deposit, looking for when magma pulses arrived into the magma chamber, and linking this to the eruptive activity as seen at the surface, as well as the signals that were recorded by the Icelandic scientists monitoring the eruption as it happened. We will then discuss our results with Icelandic colleagues in order to improve our model for the plumbing beneath the volcano, better understand the linkage between magma supply and eruption style and to better relate monitoring signals to magmatic processes.

1. Through the involvement of the British Geological Survey, and with communication and collaboration with the Icelandic research community, we hope to strengthen links and provide new tools for interpretation should a similar event occur in future.

2. As the key scientific authority advising the Cabinet Office regarding volcanic hazards, the role of the BGS in this project is to take forward any insights gained for direct application should similar events occur in future. This would not only relate to Icelandic volcanism, but could also be relevant in any future crisis where British citizens or interests were involved. For instance, the British dependency and island volcano of Tristan da Cunha last erupted in 1961 and necessitated a full evacuation of the island. Further, in this era of global travel, there is a wide distribution of British citizens across the globe in regions where volcanic activity is occurring, and the BGS can be called upon to provide expertise to assist in mitigating emerging volcanic crises. Experience with a wide range of volcanic scenarios, coupled with a wide range of tools, is a way to improve the levels of knowledge going into a new volcanic eruption event.

3. From talking to members of the SAGE group advising COBRA during the Eyjafjallajökull crisis, and from seeing the scale of what happened during the eruption, information regarding the eruption and its consequences is critical to a successful mitigation. The vast levels of economic damage inflicted mean that any additional information that can be brought to bear during a volcanic crisis will repay its cost many times over. This is a typical observation in preparation for natural disasters - the cost of an entire monitoring and mitigation program is more than repaid economically when an event occurs. What we propose here is a two-year hind-casting study, understanding what actually happened in the magma in order to better understand similar events in future. The cost of this study is of the order of one ten-thousandth of the cost of the Eyjafjallajökull eruption to the UK economy. Whilst it will not shorten the duration of a future eruption, it can lead to better understanding, and through this, better planning and distribution of resources should a similar event occur again; one of the main problems posed by the Eyjafjallajökull eruption was the uncertainty caused by its intermittent nature and extended duration.

4. As described above, the grant will provide funding for a post-doctoral research assistant to be trained in detailed petrological and diffusional analysis. Even should they do not stay in this field, this project trains a numerate, scientific individual who can be an asset to many industrial and economic sectors.