Summary

Knowledge of past deep-ocean current speeds has the potential to inform our understanding of changes in the climate system on glacial-interglacial timescales as these may be used to help constrain changes in deep-ocean circulation rates and pathway. The Rockall Trough, a deep water basin offshore Ireland and UK, is known to be the pathway for the exchange of water masses in the North Atlantic (New & Smythe-Wright, 2001), but limited data exists to date on the changes in ocean circulation over time in this part of the Atlantic Ocean. Previous works on deep-water sedimentation in the region have recognised the presence of thick sediment bodies related to the flow of deep-ocean currents, including the Feni Drift and contouritic deposits on the eastern side of the Rockall Trough (Stoker, 1998). Proxies obtained from deep-water sediment cores, such as the mean size and percentage of sortable silt, can be used to assess the variations in the speed of bottom currents (Mao et al., 2018; Spooner et al., 2018).

This project will utilise a series of sediment cores from the continental slope and deep Rockall Trough, for which a chronostratigraphy is already established, to investigate fluctuations in current vigour using grain size measurements with a focus on the sortable silt fraction.

Objectives of the Research:

1. Carry out high-resolution grain size analyses on a selection of sediment cores from  the Rockall Trough.

2. Analyse variations in grain size data, with a focus on sortable silt.

3. Reconstruct fluctuations in ocean currents over time.

Methods to be used:

The MRes candidate will work on marine sediment cores currently stored at Ulster University and will use data already available such as X-radiograph, radiocarbon dates, multi-sensor core logger data to identify suitable intervals for more refined and high-resultion analyses. The project will then focus on grain size analyses to be carried out using a Malvern Mastersizer and the statistical analysis of such results.

Skills required by applicant:

The project is suitable for a self-motivated applicant with Earth Science, Geology, Geography, Environmental Science or Marine Science background, with capacity to learn new analytical techniques and basic statistical analysis.

References:


Mao L., Piper D.J.W., Saint-Ange F., & Andrews J.T. (2018). Labrador Current fluctuation during the last glacial cycle. Marine Geology, 395: 234-246.
New A.L. & Smythe-Wright D. (2001). Aspects of the circulation in the Rockall Trough. Continental Shelf Research 21: 777–810


Spooner P. T., Thornalle, D. J. R., & Ellis, P. (2018). Grain size constraints on glacial circulation in the Southwest Atlantic. Paleoceanography and Paleoclimatology, 33,21–30. https://doi. org/10.1002/2017PA003232


Stoker M.S. (1998). Sediment-drift development on the continental margin off NW Britain. Geological Society, London, Special Publications 1998; v. 129; p. 229-254 doi:10.1144/GSL.SP.1998.129.01.15


Essential criteria

  • To hold, or expect to achieve by 15 August, an Upper Second Class Honours (2:1) Degree or equivalent from a UK institution (or overseas award deemed to be equivalent via UK NARIC) in a related or cognate field.

Funding

This is a self-funded MRes opportunity.


Other information


The Doctoral College at Ulster University


Reviews

Profile picture of Michelle Clements Clements

Completing the MRes provided me with a lot of different skills, particularly in research methods and lab skills.

Michelle Clements Clements - MRes - Life and Health Sciences

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Profile picture of Carin Cornwall

I would highly recommend Ulster University as you get so much support.  Coleraine is a beautiful town and the people are so friendly. It was a really positive experience.

Carin Cornwall - PhD Environmental Sciences

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