The origins of volcanic lightning

Volcanic lightning can provide a spectacular addition to an ongoing eruption, but remains a significant, yet under-investigated natural hazard. Volcanic plumes distant from the eruption site are also electrically charged, which affects their lifetime and evolution. Beyond the immediate impact on air travel, charging is therefore important for understanding the meteorological effects of volcanic plumes. (It may also have planetary applications, with possible relevance to the origin of life.) However, the generation and consequences of charge in volcanic plumes are very poorly understood. This project will take a variety of approaches, following the interests and skills of the student, to investigate and quantify the relative significance of the different mechanisms currently thought to be responsible for plume charging.

  • Laboratory experiments to measure the frictional charging (triboelectricity) of ash samples from volcanoes with different levels of lightning activity
  • Modelling of triboelectric charging in a population of particles of different sizes, compositions and shapes
  • Investigation of the role of radioactivity in plume charging using laboratory experiments, in-situ observations and theoretical work
  • Laboratory experiments to investigate the significance of fractoemission – the release of charge when rocks break up – which is thought to produce significant charging near the vent