1-1-1-1-1-1-1-1-1-1-1-1-1-1 From: Jan Lindsay <j.lindsay@xxxxxxxxxxxxxx> *Seeking PhD candidate on base surge hazard in the Auckland Volcanic Field, New Zealand * Background: Auckland, New Zealand's largest city, sits upon the active, basaltic, intraplate Auckland Volcanic Field (AVF). The AVF is an area of distributed volcanism characterized by ~53 small monogenetic volcanoes in the form of scoria cones, maars, craters, and a small shield volcano (Rangitoto) that have formed over the past 193,000 years. Mantle melts are thought to ascend rapidly to the surface with little crustal storage, and there is great interest from Auckland stakeholders to better understand what might happen when magma arrives at the surface in a future eruption. Over 80% of past eruptions are thought to have begun with a phreatomagmatic phase forming maars and tuff rings, with tephra fall, base surges, and ballistic projectiles as the main processes, with subsequent magmatic phases forming scoria cones, and in most cases, lava flows. However, although past workers have inferred that phreatomagmatism occurs early in the eruption sequence, the possibility that it might have occurred later in the sequence (fully obliterating any earlier deposits) has yet to be fully tested. Furthermore, recent research on analogue distributed volcanic fields in the US by Valentine et al. (2022; https://doi.org/10.1029/2022GL100561 <https://urldefense.com/v3/__https://doi.org/10.1029/2022GL100561__;!!IKRxdwAv5BmarQ!eCYhkd6rsIxTT5JxlgfQzaOOM2m-VSIfDPa3L8iCTShx0RsGB4Y3MGFKagTl9hCFcivbd0REwWFK5T6QQFVagb1E5w$>) has prompted us to consider revising credible base surge run outs in Auckland. These open questions, together with a planned review of the Auckland Volcanic Field contingency plan, have motivated this project. Position description: The successful PhD candidate will work at the University of Auckland (UoA) under the primary supervision of Jan Lindsay, with co-supervision from James White at the University of Otago. Other supervisors will likely join the team as the project evolves. The proposed project is interdisciplinary, and will explore the geology, hazard, and potential impacts of base surges in Auckland. This will involve thorough fieldwork in the AVF combined with interrogation of borehole and tephrochronological data to better understand past base surge behaviour in Auckland. This volcanological information will be combined with insights from analogue volcanoes and numerical models to develop a clearer picture of the credible ranges in magnitude (including run out) of future surges in the AVF. These new insights will allow a first order impact assessment for base surge in Auckland. Engagement with stakeholders will occur throughout, to ensure insights and outputs are useful for informing mitigation planning. Key research questions to be asked include: - What are the implications of the Valentine et al. (2022) Ubehebe study for Auckland? - Is this volcanic centre in Death Valley an appropriate analogue for the Auckland Volcanic Field? - Studies of existing AVF centres have shown that base surges tend to occur in the initial phases on an eruption sequence. How likely is it that base surges have occurred (or will occur) during, or even at the end, of an AVF eruption? - What are the main factors controlling the timing of phreatomagmatism within an eruption sequence? - What is the range in possible run out distances for future AVF base surges? - How will base surge impacts in the Auckland context attenuate with distance from vent? The project is part of the Determining Volcanic Risk in Auckland (DEVORA) Research programme, which will provide an annual stipend ($NZ 33,000 in 2024), with annual CPI adjustment, and will cover compulsory tuition fees and insurance for this project at the University of Auckland. How to Apply: We invite applications from students with an MSc or similar level degree (or who will obtain this qualification before commencing their doctoral study) in a relevant topic, which may include earth sciences, geology or volcanology. Candidates will have experience and interest in physical volcanology and numerical modelling; experience and interest in distributed volcanism, tephrochronology, and geotechnical data analysis will also be advantageous. Please send an expression of interest by emailing a CV, academic transcript, and brief cover letter to Jan Lindsay: j.lindsay@xxxxxxxxxxxxxx by 20 June 2024. 1-1-1-1-1-1-1-1-1-1-1-1-1-1 ------------------------------
