PhD Candidate to research the climatic change on the Greenland Ice Sheet over the Late Cenozoic

Department of Earth Sciences

PhD Candidate is sought for a fully funded PhD program at Durham University (UK) in the Departments of Earth Sciences and Geography to research the climatic change on the Greenland Ice Sheet over the Late Cenozoic to establish lineages to future climate change. The project will be supervised by David Selby, Emma Ownsworth (Earth Sciences), Jerry Lloyd (Geography) & Paul Knutz (GEUS).

Overarching aim: To investigate the link between the development of major glaciation of the northern GrIS and the intensification of northern hemisphere glaciation at approximately 3 Ma, and the amplitude of variability of northern GrIS through the Pleistocene, particularly focussed on the Mid Pleistocene Transition (MPT). This project will benefit from the major international research effort and support associated with International Ocean Discovery Program Expedition 400 (IODP 400) ‘NW Greenland Glaciated Margin’.

1. Project Overview

Recent studies have highlighted the sensitivity of the Greenland Ice Sheet (GrIS) to future climate warming with significant implications for global sea-level rise and impacts on the Atlantic Meridional Overturning Circulation. Understanding the past evolution of the GrIS and the interaction with broader climate changes is key to improving our understanding of the potential future response of the GrIS to ongoing climate change. Yet, there are significant gaps in our knowledge in respect to the evolution of the GrIS associated with past climate changes. For example, the detailed evolution and cycles of growth and decay of the GrIS during the time period covering the Pliocene through the Pleistocene (the last 4 – 5 million years) that encompasses numerous fluctuations between warmer and cooler climates. To address these questions the project will build on ongoing research developing and applying a novel technique, osmium-isotopes, to reconstructing ice sheet dynamics associated with development and growth of a Northern GrIS onto and across the continental shelf into the marine environment. Utilising seafloor sediment cores our recent research shows osmium-isotopes can be used to track periods of increased delivery of continental material due to glacial erosion out to the Greenland continental margin and into Baffin Bay (Ownsworth et al., 2023). The osmium-isotope signal in marine cores is, therefore, sensitive to the growth and expansion of the GrIS onto and across the continental shelf during colder intervals and subsequent retreat from the shelf during warmer intervals.

2. Aims and methods

Research will principally involve geochemical analyses (osmium-isotopes) but will also include additional sedimentological and microfossil analyses (e.g. foraminiferal analysis, total organic carbon (TOC), XRF scanning, x-rays and multi-sensor core logging). Osmium data will be compared to the well-established proxies collected from the same cores (in collaboration with international partners on IODP 400) and used to reconstruct environmental changes. Specifically, the osmium-isotopes will be used to investigate sediment delivery from the Greenland landmass via glacial erosion and track the development and evolution of the northern GrIS into a tidewater environment onto and across the continental shelf. The sensitivity of the osmium isotope signature to terrestrial-sourced vs open ocean sourced material will provide a detailed understanding of the more subtle changes in sediment provenance linked to past climate changes and, ultimately, the sensitivity of northern GrIS to climate change.

3. Training

The student will receive training in core analysis and in sediment core description (Durham and GEUS). Training in state-of-the-art osmium isotope geochemical analyses will be provided in a world leading laboratory in the Department of Earth Sciences, Durham. Training in additional proxy techniques (microfossil, sedimentological and geochemical teachniques) will be provided in state-of-the-art laboratories in the Department of Geography, Durham and GEUS.

References & reading

Ownsworth et al., 2023. Tracking sediment delivery to central Baffin Bay during the past 40 kyrs: Insights from a multiproxy approach and new age model. QSR. DOI: 10.1016/j.quascirev.2023.108082

Rooney et al., 2015. Tracking millennial-scale Holocene glacial advance and retreat using osmium isotopes: Insights from the Greenland ice sheet. Quaternary Science Reviews 138, 49-61.

Tan et al., 2018. Dynamic Greenland ice sheet driven by pCO2 variations across the Pliocene Pleistocene transition. Nature Communications 9, 4755. DOI: 10.1038/s41467-018-07206-w.

Further information

Prof David Selby email via form at https://www.dur.ac.uk/staff/d65d2f66/

Applications deadline June 30th 2024.

published: 25 April 2024     Please mention EARTHWORKS when responding to this advertisement.