- Graduate Position
The following PhD project is available in New Zealand.
Climatic and environmental impacts of the youngest supereruption on Earth
Rapid changes in Earth's climate have been documented after historic explosive volcanic eruptions such as Pinatubo 1991. However, the magnitude of the largest explosive eruptions represented in the geological record far exceeds those witnessed in modern history, by up to two orders of magnitude. Through simply scaling the measured impacts of historic volcanic eruptions, it has been proposed that supereruptions may have caused major shifts in Earth's past climate. Few opportunities exist to study supereruption deposits in sufficient detail to understand their impacts, but New Zealand is THE place to do this. The central North Island is host to the most productive region of active silicic volcanism on Earth, which produced the most recent supereruption known, at 25.5 ka. This PhD project will investigate the climatic and environmental impacts of the 25.5 ka Oruanui supereruption using Antarctic ice core records. The Oruanui supereruption has been recently identified in the high?resolution West Antarctic Ice Sheet divide ice core (WDC?06A) through the presence of a large sulfate peak and volcanic glass shards, opening up the possibility to critically assess the impacts of this event. The student will investigate at least three other ice cores that cover the same time interval using existing ice core geochemistry and particle analysis as a sampling guide. The presence of Oruanui glass provides a critical geochemical fingerprint of the supereruption and a time marker to interrogate the surrounding ice record for a range of climatic and environmental proxies. The student will further analyse the volcanic horizon for bioavailable iron and phytoplankton proxies to investigate the potential biological impacts of the supereruption through ash fertilisation of the Southern Ocean. This research will provide the first insights into the impacts of a supereruption over short (years), medium (decades) and longer (centuries or more) time intervals. We are looking for a student with a strong background in one or more of the following: palaeoclimate research, ice core research, microanalytical geochemistry, marine chemistry/ biogeochemistry. As part of a wider research programme funded by the Royal Society of New Zealand Marsden Fund, this project will proceed in parallel, interact and work closely with a second PhD student and gain experience in a variety of labs and analytical facilities in NZ and the USA.
Supervisors: Simon Barker (VUW), Holly Winton (VUW), Nels Iverson (New Mexico Tech), Michael Sigl (University of Bern)
Stipend: NZ$35,000 + fees (3 years), international travel for conferences and analytical work
Funding provided by 3 year Marsden project: “Climatic and environmental impacts of the largest explosive volcanic eruptions on Earth”. Based at Victoria University of Wellington.
Ideal starting date: Mid to late 2022