PhD position: High-resolution reconstruction of past water quality using innovative non-destructive core scanning techniques in New Zealand lake sediments


Primary Supervisor: Dr. Chris Moy, Dept. of Geology, University of Otago, New Zealand

Co-supervisors: Dr. Sebastian Naeher and Dr. Marcus Vandergoes (GNS Science)

Description: New Zealand lakes are fragile ecosystems, some of which are under threat due to agricultural practices in their catchments, land-use changes, urbanisation, pollution, and climate change. A primary goal of the Lakes380 project is to study paleoenvironmental indicators preserved in lake sediment cores to learn how water quality has changed in the past and how lakes respond to environmental and climate change. The perspective obtained from these records can be used to evaluate future sustainability and inform restoration and management strategies for lakes.

We are currently seeking a Ph.D. student to investigate the climate and anthropogenic drivers of water quality change in New Zealand lakes using recently developed non-destructive core scanning techniques. The successful applicant will apply innovative hyperspectral core imaging technology, originally developed for satellites, to generate detailed records of pigments and combine these datasets with high-resolution x-ray fluorescence elemental profiles. Complimentary stable isotope and organic geochemical measurements will be used to develop and test proxies arising from the non-destructive analyses. Together, these data sets will be used to examine how climate and environmental change influence lake ecosystems. The project has a particular focus on the last millennium, covering the interval of first human arrival to the islands, but opportunities exist to extend some of these observations through the Holocene.

This PhD project will involve: 1) lake coring; 2) the use of existing and new Lakes380 sediment cores; 3) generating high-resolution pigment and elemental records to evaluate past changes in water quality, environmental conditions and climate; and 4) integrating these data with established paleoclimate records. The successful applicant will be based at the University of Otago, but will take advantage of facilities at both GNS Science and Otago to carry out this work: 1) A Uwitec piston coring system capable of collecting sediment cores up to 25 m in length; 2) non-destructive instrumentation within the newly established Otago Repository for Core Analysis (ORCA), including a new Itrax XRF scanner; and 3) the new hyperspectral core imaging facility at GNS Science.

The project is ideal for individuals with multidisciplinary interests in climate science, geochemistry, paleoecology and sedimentology. We are seeking an individual who has enthusiasm for field work, experience working in a geochemistry laboratory and demonstrated research experience (MSc preferred; BSc with honors thesis considered). The successful candidate must be competitive for a University of Otago Doctoral Scholarship, which includes a 3-year stipend of NZ$27,000 per year (tax free and includes a fee waiver), research costs, and travel support to national and international conferences. Both New Zealand and international students are encouraged to apply. Criteria for scholarship eligibility should be addressed in your application materials and can be viewed here: https://www.otago.ac.nz/graduate-research/scholarships/phd/index.html

Review of applications will begin on July 1st and will continue until the position is filled. The appointment will be based in the Department of Geology and can be begin at any time from September 2020. Applicants should submit a single pdf file by e-mail to Chris Moy (chris.moy@otago.ac.nz) and Sebastian Naeher (s.naeher@gns.cri.nz) with: 1) a cover letter including preferred start date, 2) a complete CV, 3) academic transcripts (unofficial ok), and 4) the names and contact information of two referees. We are more than happy to answer any questions about this project.

posted: 03 June 2020     Please mention EARTHWORKS when responding to this advertisement.