It has been suggested that the release of glacial flour phosphate to the Neoproterozoic Ocean, 712-635 million years (Myr) ago, stimulated the Neoproterozoic Oxygenation Event (NOE) and emergence of photosynthetic eukaryotic algae to prominence. However, preliminary work for the Sturtian Snowball glacial deposits in Islay, Scotland deposited 717-650 Myr ago, point to a bulk of this P locked in glacial rock flour only became bioavailable through CO2-driven chemical weathering of the ocean-wide dispersed glacial debris, following the deglaciation of the Sturtian Snowball. CO2-Cryobiosphere aims to test this hypothesis on glacial rock flour samples from modern melting glacials, linked to laboratory CO2 weathering regimes, dissolved nutrient enrichment in seawater and impact on the prolific Prochlorococcus and Synechococcus photosynthetic cyanobacteria that first emerged to global prominence during the Neoproterozoic.
Project Aims and Methods
The aim of this project is to develop an empirical understanding on how glacial nutrients (particularly phosphate) became available to life in the Neoproterozoic oceans and how this contributed towards the oxygenation of the biosphere to present day levels. To achieve this, glacier flour will be collected from glacials terminating in the sea and rivers in the Arctic, the Canadian Rocky Mountains and Northern Sweden. After comparative chemical and mineralogical analysis, these samples will be incubated under Neoproterozoic seawater conditions in present day atmospheric levels (PAL) of CO2 and up to the 350x PAL concentrations believed to have been present during the post-Snowball Neoproterozoic Super-greenhouse state. The impact of chemical weathering and the release of nutrients into solution will be quantified and their impact on rates of primary production assessed on photosynthetic cyanobacteria, Prochlorococcus and Synechococcus. Experiments will be accompanied by Sr isotope analysis to measure weathering intensities, O isotopes in phosphate to assess biotic and abiotic phosphate cycling pathways and C and N isotopes to assessed impact on the fractionation of C and N isotopes by comparison with sedimentary signals, Sr isotopes and nutrient levels across the Sturtian Snowball glaciation on Islay and the Garvellach Island, Scotland.
The successful applicant for this position would have a good background in the Earth Sciences. They should be willing to perform multidisciplinary research by undertaking cutting-edge research tasks in geomicrobiology, geochemistry and biogeochemistry over large geological timescales.
CASE or Collaborative Partner
Describe how partner enhances project and student experience (approx. 80 words)
The student will be exposed to world-class stable isotope facilities, working closely with facility staff to learn both laboratory techniques for the extraction of phosphate oxygen isotopes and have hands on experience running several stable isotope mass spectrometers. This will provide the student with a good laboratory working background and the experience of working away from their host institution.
The candidate will obtained a PhD degree in biogeochemistry, requiring multidisciplinary skills in geomicrobiology, geochemistry and biogeochemistry. Through working within a strong network, they will acquire international collaboration skills, present their work at major international conferences and publish in high standing and reputable peer review journals. There will be opportunities to travel to some amazing locations in Canada, Sweden and in the Arctic for sampling.
UK Research Council eligibility conditions apply
Open to UK and EU students. All EU applicants must have been ordinarily resident in the EU for at least 3 years prior to the start of their proposed programme of study.
Applicants from EU countries who do not meet the residency requirements may still be eligible for a fees-only award.
How to apply:
You should apply to the Doctor of Philosophy in Earth and Ocean Sciences with a start date of October 2020, including:
an upload of your CV
a personal statement/covering letter
two references (applicants are recommended to have a third academic referee, if the two academic referees are within the same department/school)
current academic transcripts..
In the research proposal section of your application, please specify the project title and supervisors of this project and copy the project description in the text box provided. In the funding section, please select ’I will be applying for a scholarship/grant’ and specify that you are applying for advertised funding from NERC GW4+ DTP.
If you wish to apply for more than one project please email [email protected]
The deadline for applications is 16:00 on 6 January 2020.
Shortlisting for interview will be conducted by 31 January 2020.
Shortlisted candidates will then be invited to an institutional interview. Interviews will be held in Cardiff University between 10 February and 21 February 2020.