Advanced mineralogy technology reveals that the surface chemistry of ash particles is determined by volcanic activity
New research led by researchers in Munich and Liverpool has shown that different types of activity during volcanic eruptions determine which minerals are concentrated at ash particle surfaces. Using cutting edge QEMSCAN technology, more common in the mining industry, the researchers were able to efficiently measure the distribution of minerals and glass across thousands of ash particles.
Adrian Hornby of Ludwig-Maximilians-University in Munich (LMU), the lead author of the study, said ‘QEMSCAN is an automated mineralogy technique that rapidly classifies the mineralogy of a sample. The great advantage is that this technique distinguishes the phases in thousands of ash particles, producing a large and robust dataset that allows new methods of analysis. What we found was that some minerals, particularly feldspar and glass, occurred in different amounts at ash particle surfaces, and the variation depends volcanic activity and fragmentation processes that produced the ash’
Ulrich Kueppers, of LMU Munich added, ‘Volcanic ash presents unique hazards to aviation, health and the environment, and ash particle surfaces are where most interactions take place. The chemistry and mineralogy of ash surfaces is essential in understanding and predicting this hazard’.
In 2010, thousands of flights were cancelled across Europe and the Atlantic as the Icelandic volcano Eyjafjallajökull produced a widespread plume of ash across flight corridors. The eruption caused billions of Euros of losses to airline companies and economies, and generated a demand for improved knowledge of volcanic ash and its potential for hazard.
A substantial research group at LMU, led by Prof Don Dingwell, are investigating different aspects of the hazard from volcanic ash, including the development of new thermal boundary coatings. Wenjia Song leads a prestigious Volkswagen Freigeist project to develop novel thermal barrier coating for jet engines, while the VAsCo project is a broad collaboration with industry, including Airbus, to better understand the resilience of thermal barrier coatings. LMU has also provided the hub for a large training network for PhD students in improving the understanding of hazards from volcanic ash (VERTIGO), as well as groundbreaking research into the generation of volcanic lightning.
The study, published in Scientific Reports, presents a breakthrough in understanding fragmentation controls on ash particle surface chemistry. But this is just the start, said Adrian, whose EU-funded project AVAST seeks further insights ‘We now have 50 times more QEMSCAN data than we analysed is this study, with about half a million volcanic ash particles measured’ Adrian said. ‘Our research is becoming more fundamental, as we produce ash in controlled laboratory experiments. This allows us to learn exactly how different fragmentation processes produce size, shape and chemical differences of volcanic ash particles. Within the next year we expect to publish important advances linking volcanic activity to ash properties, and importantly, how this may allow us to predict specific ash properties and hazards based upon observation of activity during volcanic eruptions.’