University of Waikato

https://www.waikato.ac.nz/

Homepage: https://habitablearth.com/

Description:

How has Earth’s surface remained habitable for over 4 billion years? This PhD project will investigate how Earth’s surface temperature and ocean chemistry have evolved through time, with a particular focus on the early Earth. Despite decades of research, fundamental questions remain about whether early Earth climates were significantly warmer than today and how long-term carbon cycle feedbacks maintained stable conditions. This project will use oxygen isotope geochemistry of iron-rich sedimentary rocks to develop new constraints on past environmental conditions. These materials represent an underexplored archive of seawater chemistry and climate and offer the potential to resolve long-standing uncertainties in Earth history.

The goal of this project is to generate new geochemical constraints on past temperature and ocean conditions using sedimentary rock records spanning the Archean to present. This will involve applying oxygen isotope techniques to iron-rich phases and evaluating how environmental and geological processes influence isotope signatures.

Overall, the project will produce new geochemical datasets from ancient sedimentary archives, improve constraints on Earth’s temperature and ocean evolution, and contribute to publications in leading international journals.

Prior experience

Experience in one or more of the following areas is desirable: isotope (or other) geochemistry, geology, global biogeochemical cycling, carbon cycling, or modelling.

As part of your application package, kindly include:

1. CV (including 2–3 referees)
2. Cover letter outlining: your motivation for undertaking a PhD; relevant experience; research interests.

Applications will be reviewed as they are received until the position is filled
(priority deadline: 30 April 2026)

Kindly email your application to: tisson@waikato.ac.nz