PLEASE NOTE: Application deadline date 08 Jan 2024. Applications are no longer being accepted for this project
Project Overview
This project will reconstruct the explosive history of Santorini volcano and the activity in its caldera, through fluid and sediment geochemical analysis of new sediment cores and advanced numerical modelling to characterize the chemical and physical processes.
Project Description
Submarine caldera volcanoes produce the largest and most devastating volcanic eruptions on the planet. Yet the fundamental controls on the explosivity of these eruptions remains poorly understood. A fundamental unknown is the role of hydrothermal fluid circulation. Hydrothermal fluids carry geochemical signatures of the volcanic system, which tell us about its activity and the sediments around these systems record these signatures, providing a record of past volcanic activity.
This project will reconstruct the history of the Santorini caldera1 (offshore Greece) using sediment cores to be collected during a scientific expedition. Changes in volcanic activity will be measured and interpreted by analysing the compositional and geophysical changes in the sediment, such as grainsize, structure, metal content and Eu+ anomalies2. To understand the current activity of the volcano, the fluids in the sediment cores will be analysed for their composition, e.g. for metals, anion, methane, nutrients and Sr isotopes. The geochemical and sedimentological results will be brought together in a coupled thermo-hydro-chemical model that can then be used to predict the future behaviour of the system3.
The results of this PhD project will produce new understanding of how submarine calderas develop with time and how fluids can be used to predict changes in the magmatic systems. This project is part of the NERC funded HYDROMOX project, which aims to understand the controls on caldera explosivity. The PhD student will be joining a large, international project team. Alongside seagoing fieldwork, the student will have the opportunity to participate in research collaboration visits and present at international conferences.
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners.
The student will be registered at the University of Southampton and hosted at the National Oceanography Centre. Specific training will include: Seagoing, sediment and pore fluid analyses e. g. for cations (ICP-OES, ICP-MS), anions (IC), nutrients (AA), core logging, ITRAX (XRF) non-destructive geochemical logging, XRD and reactive transport modelling of multiphase fluids in porous media using TOUGHREACT. The student will join the vibrant and dynamic Ocean Biogeochemistry Group at NOC and the Geochemistry Research Group at the University of Southampton; regular (bi-weekly or as needed) meetings with members of the supervisory teams will be scheduled. There will be plenty of opportunities to engage with other PhD students, researcher and research projects and access to unique research facilities (e.g. BOSCORF).
(1) Druitt, T.H., Mellors, R.A., Pyle, D.M. and Sparks, R.S.J., 1989. Explosive volcanism on Santorini, Greece. Geological magazine, 126(2), pp.95-126.
(2) Dutrieux, A. M., Lichtschlag, A., Barriga, F. J., Martins, S., Milinovic, J., & Murton, B. J. (2023). Metal Preservation and Mobilization in Sediments at the TAG Hydrothermal Field, Mid‐Atlantic Ridge. Geochemistry, Geophysics, Geosystems, 24(6), e2023GC010879.
(3) Marín-Moreno, H., Bull, J. M., Matter, J. M., Sanderson, D. J., & Roche, B. J. (2019). Reactive transport modelling insights into CO2 migration through sub-vertical fluid flow structures. International Journal of Greenhouse Gas Control, 86, 82-92.
