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-resolution 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
Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.
We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.
In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.
Submission deadline
Friday 5 June 2020
12:00AM
Interview Date
Week commencing 22 June 2020
Preferred student start date
mid September 2020
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