PhD Title: Critical Eruptive controls of an Intra-plate volcano, Ascension Island, South Atlantic

My PhD focusses on reconstructing evolving eruption dynamics of explosive-effusive volcanism on Ascension Island, South Atlantic. By integrating field observations, analyses of pumice clast density and texture, and compositional data I have been reconstructing how bubble networks form and are influenced by internal and external factors to facilitate/inhibit outgassing and lead to changes in eruptive style.

The Zeiss-GSL scholarship I was awarded in 2019 has enabled me to pursue 3D analysis of clasts from three distinct eruptive scenarios on Ascension Island:

- A compositionally zoned pumice fall

- A basalt-rhyolite mingled pumice fall

- An explosive-effusive transition

I will use this study to investigate how melt-gas-crystal relationships evolved for these three eruption scenarios to see how eruption dynamics evolve for magmas with different starting conditions.

Ultimately, the goal of my research is to better understand how these alkali-rich melts on Ascension behave during ascent, and how this impacts the eruptive style of a volcano over time in order to better inform volcanic hazard assessment.

I have used a variety of analytical techniques thus far:

- XRF analyses of clast composition

- Backscattered SEM image acquisition and then analysis using ImageJ

- 3D X-ray computed micro-tomography

- XCMT data processing in Avizo

- Ion probe analyses of volatile content

- Bubble size distribution analysis on 2D and 3D datasets

- WDS and EDS analyses of thin sections.

Research Interests:

- Volcanology

- Ascent dynamics of volcanic eruptions

- Field studies of volcanic deposits

- Textural investigation of volcanic products

- Volcanic hazard

- Science communication and outreach