Cardiff University President's Research Scholarship: Living archives of recent climate change (Climate Change: confronting the four 'grand challenges') (PhD Studentship)
Reference Number: R936
Key Studentship Information
Project title: Living archives of recent climate change
Rationale:
Annually resolved growth lines in the shells of marine molluscs are yielding important multi-centennial archives of marine climate change. It has recently been shown that the shell of the very long-lived bivalve molluscs Glycymeris glycymeris and Arctica islandica can be used to build long chronologies for the shelf seas surrounding the North Atlantic Ocean. These growth line series have powerful applications and are now being utilised in high-resolution palaeoceanographic reconstructions. Accurate constraints on past ocean temperatures are critical for documenting climate change and resolving its causes. This project aims to develop quantitative multi-proxy palaeothermometery calibrations using trace element ratios (e.g., Sr/Ca) and the highly promising ‘clumped isotope’ composition of aragonite bivalve shells grown under controlled environmental conditions (at School of Ocean Sciences, Bangor University). The new proxies will be applied to fossil shells collected from the Northwest European Shelf Seas to obtain a novel high-resolution record of recent climate change.
Methodology:
Selected shells will be analysed for (i) their trace element content using a New Wave Research 213nm Laser Ablation system, coupled to a Thermo X Series 2 Inductively Coupled Plasma -Mass Spectrometer (LA-ICP-MS) at Cardiff University. Alongside Sr/Ca and Mg/Ca data, the isotopes 27Al, 55Mn and 57Fe will be collected for the purpose of screening for diagenetic alteration when the technique is applied to fossil samples. (ii) "Clumped isotopes" based on mass 47 in CO2 extracted from carbonates which reflect a temperature dependent preference of 13C and 18O to create a bond with each other. The abundance of 18O-13C bonds in the CO2 (mass 47) will be measured using isotope ratio mass spectrometer (IRMS) and subsequently the '47 will be calculated, which is the offset from the expected concentration if the distribution of all isotopes was stochastic. From the '47 a temperature value can be derived that is independent of the isotopic composition of the water and the dissolved inorganic carbon the carbonate formed from. The major advantage of this approach is that in combination with the carbonate d18O, obtained by the same measurement, this method yields both the ocean temperature and the isotopic composition of the seawater.
Training:
As well as a formal programme in research and complimentary skills at Cardiff, the student will receive training in bivalve mollusc culturing and advanced sclerochronological techniques applied in palaeoclimate reconstruction. This will include the development of novel paleothermometry techniques using the isotope and elemental geochemistry from biocarbonates.
Wider implications:
The compilation of instrumental and proxy climate records over the last millennium provides clear evidence of variations in average large-scale surface temperatures, and prominence of the Earth’s climate warming during the last few decades (IPCC, 2007), however, it is also widely recognised that there is an urgent need to reduce the uncertainty and increase the spatial coverage of such compilations. This project aims to address these issues through the development of improved proxy capabilities and the generation of palaeoclimate time series using very long-lived bivalve molluscs. The study will interface with ongoing sclerochronological based collaborations between Cardiff and Bangor and will ultimately contribute to an integrated and detailed picture of climate and oceanography over the past millennium.
Supervisors: Prof Ian Hall/Dr Carrie Lear; Cardiff: Dr Martin Ziegler (also ETH), Bangor: Prof James Scourse and Dr Paul Butler
Start date: October 2013
Funding
This is a Cardiff University President's Research Scholarship. The award includes full UK/EU tuition fees plus a doctoral stipend matching UK Research Council National Minimum (£13,590 p.a. for 2012/13, updated each year).
Eligibility
Academic Criteria: Applicants must have a First Class Honours degree or a 2.1 plus a postgraduate Masters degree (or their equivalents).
Residency: The award is open to all UK/EU students without further restriction.
How to Apply
Prospective students should submit an application via the University's online application service for the programme in Palaeoclimate and Climate Systems, October 2013 start.
A CV and Covering Letter should be submitted to Christine Williams at williamsc4@cardiff.ac.uk
Application Deadline: 1 February 2013
Further Information
For further information please contact Christine Williams:
Email: williamsc4@cardiff.ac.uk
Telephone no: +44 (0)29 208 75772
