A new multi-parameter toolkit to interrogate the source and climate impact of past volcanism

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Explosive volcanic eruptions spew enormous quantities of ash and gas in to the atmosphere. There are about 5-10 major volcanic events every year, and roughly 600 million people (10 % of the world's population) live close enough to be directly affected when they erupt. These eruptions may cause lead to significant human fatalities, and can also have devastating environmental impacts, covering the landscape in ash and acidic fallout, which destroys crops and harms livestock.Although most of us in the UK will never witness one of these eruptions up close they can still have an impact on our lives. This was demonstrated by the eruption of Eyjafjallajökull volcano in Iceland in April and May 2010. Although the eruption was relatively minor and did not kill anyone, it disrupted the travel of millions of people and cost global economics billions of pounds. This emergency highlighted the vulnerability of our modern globalised world, and the fact that the UK is at constant threat from disruption by volcanic events. One of the key goals of volcanology is to study past volcanic events so that we can understand their return periods and environmental impacts, and help prepare society for the next 'big one'. Amazingly, the volcanic products from large explosive eruptions undergo regional and global distribution and can travel thousands of kilometres from their eruption source. Although in most surface environments this fallout is rapidly washed away and lost. Ice sheets are the expedition to this, and drilling into the ice and accessing core provides the undisputed best records of past volcanic eruptions. Unfortunately, reading this record of past volcanism is not straightforward, and although we can easily identify the sulphur-rich layers and ash deposited by these ancient eruptions, scientists have struggled to understand where the source volcano might be located or what its climate impact might have been. Even in records that span the last 2500 years, we only know the location of 7 of the 25 largest volcanic eruptions. If we could learn how to get more information about the likely source and environmental impacts out of these ice core records, it would represent a major breakthrough - not only would be able to help scientists target volcano monitoring in regions of the globe that are prone to large volcanic events, but by understanding the frequency and impacts of these past events we can reduce the economic impacts.My project will take advantage of recent analytical breakthroughs in ice core research. In particular, recent analyses suggest that volcanic sulphur chemistry encodes critical information about the height the volcanic plume reached in the atmosphere, and hence its climate changing potential. I'll also analyse the chemical composition of the tiny ash samples that get lofted all the way to the ice sheet (many of which are smaller in diameter than a human hair). I shall interrogate these techniques for several well-known volcanic eruptions, where we know both the source and their climate-impact. Once calibrated, I will use the technique to determine the source of unknown eruptions in the ice core record, and evaluate their climate and societal impact by comparing my results to other data sets. This project will provide critical information on the magnitude, frequency and style of past eruptions. This will lead to improved forecasts of future volcanic events. Being better prepared will help limit the loss of life and reduce the economic losses. For the UK, we'll gain a thorough understanding of the eruption frequency of large volcanic events in Iceland. For global society, we'll help pinpoint the source of past eruptions and evaluate the frequency of climate-changing eruptions on Earth.