Volcanic ash is a product of nearly all explosive volcanic eruptions and its dispersal in our atmosphere can have severe effects on air space closure and aviation safety, human health and the Earth’s climate. Magma fragmentation in the subsurface conduit generates a distribution of particles that are subsequently transported in a turbulent gas-particle mixture. During this transport additional, secondary fragmentation events caused by particle-particle collisions change the size distribution of volcanic particles that ultimately become ejected from the vent. If pyroclastic density currents form the volcanic particles are again subject to secondary fragmentation. To accurately model and reliably forecast these hazardous gas-particle mixtures a comprehensive understanding of how volcanic particles texturally evolve (e.g. size, shape) during eruption is required. This is the central goal of this PhD studentship.
Project Aims and Methods:
During this project you will perform a series of state-of-the-art fluidization experiments to determine how volcanic ash is created and further modified during transport in the subsurface conduit, eruption column and associated pyroclastic density currents (See Jones & Russell (2017) for more details and context). Experiments will use a fluidization apparatus that suspends real volcanic particles (pumice, lithics, crystals) at conditions relevant to the volcanic system. High-speed filming and image analysis will quantify the flow dynamics and particle interactions. You will also characterise the textures of the experimentally generated pyroclasts. These techniques will include laser diffraction to quantify particle size and shape distributions and scanning electron microscopy (SEM) to describe the petrographic features of the pyroclasts. Such measurements will allow for comparison to field deposits and natural pyroclasts originating from explosive, silicic volcanism.
You will also have the opportunity to combine these fluidization experiments with numerical modelling (e.g. Dufek et al., 2012). The controlled laboratory experiments will serve as key ‘ground truths’ for model development that will incorporate particle breakage into pyroclastic density current and/or conduit flow models. During the studentship you will have the opportunity to visit the University of Oregon to collaborate and develop these numerical models.
Knowledge and Skills Development:
Throughout the studentship you will be integrated into the vibrant, active postgraduate research community in the Earth, Ocean & Ecological Sciences Department. Your laboratory skills will be developed, learning methodologies to investigate and quantify features of a natural phenomenon that are otherwise inaccessible. Your numerical modelling skills will be developed during a secondment to the University of Oregon.
Further Information & Eligibility:
Previous laboratory experience would be useful along with reasonable numeracy/ modelling skills. Candidates from underrepresented groups and candidates who have followed a non-traditional education path are strongly encouraged to apply for this position. Funding is available for UK and Irish nationals only.
For further information about the project, applicants should contact Dr. Thomas Jones on email@example.com
To apply for this opportunity please visit: https://app.askadmissions.co.uk/AYApplicantLogin/fl_ApplicantLogin.asp?id=liv