PhD Studentship Opportunity: Volcano Geophysics
Multiparameter geophysical study on monogenetic volcano architecture, and the role of basement structure.
A PhD studentship funded by Devora (Determining Volcanic Risk for Auckland; http://www.devora.org.nz/ ) is available to investigate the interplay of basement and volcanic architecture at the Auckland Volcanic Field (AVF) and Whangarei Volcanic Field (WVF) using geophysical methods. Auckland is New Zealand’s largest city and the student will be awarded a degree from the University of Auckland (https://www.auckland.ac.nz/).
The project aims are to firstly understand the internal architecture of Rangitoto Volcano, the youngest, largest, and most anomalous in the intraplate AVF. Unlike other volcanoes in the AVF, recent dating indicates Rangitoto has erupted in 3 distinct episodes in the last 1500 years. Long lived activity is a marked departure from all other eruptions of the AVF and may represent a significant change in magmatism driving the AVF with important implications for future activity. It is unclear however, if Rangitoto represents a single volcano with multiple eruptive episodes from a single feeder conduit, or if it is comprised of several overlapping but genetically distinct volcanoes coincidently erupted at the same site (Needham et al. 2011). Despite extensive study, at least 5 different models of the internal architecture of the island exist (Hayward 2017) and geophysical data (existing and to be acquired) will be used to further resolve the issue to better predict future AVF behaviour.
Additionally, at the AVF the student will geophysically model the structure of Mesozoic basement beneath Auckland to investigate controls on volcano occurrence. The Mesozoic basement/Miocene Waitemata Group contact is a major physical property contrast that may affect the propagation of dykes towards the surface, hence knowing its depth and morphology is useful for providing controls on the last critical stages of ascent of magma to the surface. Uncovering hidden faults within the basement may also change understanding of the seismic hazard in Auckland. An equivalent investigation of basement control on volcanism at the little studied WVF will also be performed.
The project will be supervised by Dr Jennifer Eccles at School of Environment, University of Auckland, and Dr Craig Miller at GNS Science. There will be opportunity to work both at the School of Environment, University of Auckland (Auckland) and GNS Science (Taupo).
The student will ideally have good geophysical knowledge in potential field methods and an interest in applying them to volcanic problems, a strong maths and coding (preferably python) background and English language skills. The project will involve substantial field work and geophysical modelling using open source (SimPEG) and proprietary codes (Geosoft Oasis Montaj, GM-SYS). Aeromagnetic and variable spatial density gravity data already exist over both the AVF and WVF. Geophysical equipment available to support further data acquisition includes La Coste and Romberg gravity meters, magnetometers, resistivity imaging equipment and shallow, high resolution seismic reflection equipment.
The PhD is funded for 3 years and includes a full studentship including fees plus $27k NZD annual stipend.