COMET Associate Anja Schmidt combines volcanological data and atmospheric modelling to quantify volcanic hazards and risk. Her research provided the first quantitative assessment of the hazards arising from a future Icelandic Laki-type eruption, showing that air quality could be degraded for several weeks potentially resulting in more than 100,000 premature deaths in Europe. This work on volcanic air pollution has informed UK Government policy about the gas and aerosol particle hazards arising from Icelandic volcanism.
Icelandic volcanic eruptions
The 2010 Eyjafjallajökull and 2011 Grímsvötn eruptions in Iceland were stark reminders that society is highly vulnerable to volcanic hazards. In April and May 2010, volcanic ash clouds from Eyjafjallajökull repeatedly resulted in restrictions of controlled European airspace for commercial aviation for up to 9 days at the time. Explosive volcanic eruptions that produce volcanic ash clouds affect society most frequently. However, there have been at least four eruptions in Iceland in the past 1200 years that emitted vast amounts of toxic gas, volcanic sulphur dioxide, rather than volcanic ash.
The prime example is the 1783-1784 AD eruption of Laki, which pumped as much sulphur dioxide into the atmosphere over the course of eight months as all man-made sulphur dioxide emissions globally in 2010. This made Laki a true sulphur gas giant that emitted comparatively little volcanic ash into the atmosphere. Laki’s eruption style was similar to that of the 2014-15 fissure eruption at Holuhraun but much larger in scale and with more violent explosive phases. Once sulphur dioxide is in the atmosphere, it is chemically converted to form tiny sulphuric acid particles.
Using an advanced computer model developed at the University of Leeds, which is usually used to quantify the effects of industrial pollution, Anja simulated the dispersion of volcanic gases and aerosol particles from a Laki-type eruption. The advanced computer model not only tracks the formation and distribution of airborne particles but also their size. The latter is important in order to quantify the potential human health hazards arising from exposure to these small-sized aerosol particles.
By combining computer modelling with volcanological data, Anja was able to demonstrate, for the first time ever, the likely scale of the air quality and health impacts of a future Laki-type eruption on the European population. In 2011, her work was published in the world’s leading multi-disciplinary science journal, Proceedings of the National Academy of Sciences. In the paper, Anja showed that air quality across Europe could be significantly degraded for weeks to months in the event of a future eruption, due to an increase in the concentrations of tiny airborne particles.
Applying epidemiological evidence, she showed that there could be between 30,000 and 140,000 deaths across Europe depending on the length of exposure to volcanic air pollution in the first year of such an eruption. In other words, such an eruption could potentially cause more fatalities than seasonal influenza.
For example, for the UK the results suggest that premature mortality could increase by up to 3.5% (that is a total of up to 21,000 additional cardiopulmonary fatalities on top of about 600,000 yearly all-cause deaths in the UK).
Although volcanic ash poses the greatest threat to aviation, there is an increasing interest in quantifying and understanding the effects of volcanic sulphur species on aircraft operations. In 2014, Anja quantified the potential aviation hazards from sulphur dioxide using the Met Office’s NAME model. The research has been used to inform the aviation industry and regulators on the likely concentrations of sulphur dioxide that aircraft could encounter over Europe and the North Atlantic for a range of explosive Icelandic eruptions.
By calculating the occurrence of aircraft encounters with the volcanic plume of a short-lived (2-hour) Icelandic eruption, the researchers showed that passenger comfort (e.g. smell of volcanic sulfur in aircraft cabin) could be compromised. Although the risk of encountering high sulfur dioxide concentrations is very low (probability of 0.1%). Providing real-time information on the presence of volcanic sulfur dioxide will aid aviation risk management during and after volcanic eruptions.
This research has informed UK Government policy and led to the recognition of volcanic gas and particle hazards in addition to more established volcanic ash hazards. The data produced provided one line of scientific evidence for contingency planning. This led to a Laki-type eruption scenario being added, for the first time, to the UK National Risk Register in 2012.
The research carried out at the University of Leeds has also led to closer collaborations with the UK Government, the Met Office and the British Geological Survey to provide further evidence on potential hazards from Icelandic volcanic eruptions. Anja is now also a member of the Scientific Advisory Group for Emergencies run by the UK Cabinet Office and was involved in proposing and conducting a modelling project led by the Met Office funded by Civil Contingencies Secretariat, which provided further evidence for the National Risk Register.
The UK Government benefited from provision of scientific evidence for the National Risk Assessment. This will facilitate preparedness for future eruptions and resilience of society to volcanic eruptions is increased through contingency planning, monitoring data and forecasting of volcanic pollutants. Overall this will increase the capabilities of the UK Government, scientists, public health and aviation sectors to respond appropriately, which in turn will minimise disruption, costs and potentially save lives.