2024-B23 Dating the Icelandic lowland glaciation: Implications for Greenland Ice Sheet Vulnerability

Project highlights

Make new measurements and models of the initial growth rate of the Iceland Ice Sheet, and compare with existing models of Greenland Ice Sheet growth.
Assess implications for near-future Greenland Ice Sheet melt and consequent global sea-level rise.
Work within an international, cross-disciplinary team spanning glaciology and geology, and receive comprehensive training in scientific techniques and public outreach.

Overview

Vulnerability of the Greenland Ice Sheet (GIS) to current climate warming, which could provide c. 7 m of dangerous sea-level rise if it melted completely, is a first-order global concern. GIS melt has already begun, but it is unclear whether it will gain pace significantly over the coming century, or what the associated sea-level rise will be.

To address this concern, the international research community wishes to measure how the GIS grew to its current extent. During the Mid-Piacenzian Warm Period (MPWP), c. 3.2 million years ago, atmospheric CO2 concentrations were similar to present, and global temperature was as predicted for the coming century. Prior to the MPWP, the GIS was limited to a smaller upland area. As global temperature cooled after the MPWP, the GIS expanded rapidly to near its current extent. If we could measure the speed of initial GIS growth, it would be valuable in calibrating model forecasts of melt.

Reconstructing growth of the GIS is a 10s-of-million-dollar endeavour that requires deep drilling of marine sedimentary successions in iceberg-infested seas. Several international scientific drilling expeditions to collect this dataset are planned, but it will be >10 years before they bear full fruit.

Here, we propose to get an indicative answer on the cost- and time-frame of a PhD project by exploiting the adjacent Iceland Ice Sheet (IIS) as a GIS analogue. The IIS also advanced rapidly from the uplands to the coast after the MPWP. Crucially, this advance is recorded by easily accessible sedimentary rocks in northeastern Iceland, and we have £40k of confirmed NERC facility funding to improve age resolution by a factor of >10. The PhD student will join a Birmingham-led, international, cross-disciplinary team to measure initial advance of the IIS, explore implications for the GIS, and pave the way for a NERC-funded study.

Figure 1: The Greenland and Iceland Ice Sheets. During the last glacial maximum, both ice sheets extended as far as the edges of their continental shelves. The yellow circle shows the sedimentary archive of Icelandic lowland glaciation that this project will analyze. Greenland Ice Sheet vulnerability is shown in terms of ice loss between 2003 and 2019 superimposed as a colour scale; most of the ice sheet margin lost c. 1 m per year. Credit: NASA.

Host

University of Birmingham

Theme

Climate and Environmental Sustainability
Dynamic Earth

Supervisors

Project investigator

Stephen M Jones (U Birmingham; [email protected])

Co-investigators

Nicholas Barrand (U Birmingham; [email protected])

Marco Maffione (U Birmingham; [email protected])

Ed Gasson (U Exeter; [email protected])

Jon Todd (Natural History Museum; [email protected])

Dan Barfod (NERC National Environment Isotope Facility)

Jonathan Hall (Natural England; [email protected])

Benjamin Keisling (U Texas)

Áslaug Geirstóttir (U Iceland)

How to apply

Each host has a slightly different application process.
Find out how to apply for this studentship.
All applications must include the CENTA application form.
Choose your application route

Methodology

The PhD dissertation will centre around 3 papers submitted to peer-reviewed journals.

Paper 1. We have already dated the lower Tjörnes succession (Hall et al., 2023). The doctoral researcher (DR) will follow this template to integrate new radiometric ages with magnetostratigraphy and build a new age model for the upper Tjörnes succession.

Paper 2. From Paper 1 we have: (i) onset age of lowland glaciation; (ii) durations of the six oldest lowland glacial-interglacial cycles. Icelandic collaborators provide: (iii) age and extent of upland glaciation. The DR will work with Birmingham and external supervisors to develop the first palaeo-icesheet model that satisfies these constraints.

Paper 3. Working alongside our international project team of glaciologists, the DR will (i) compare our new observationally ground-truthed constraints on IIS expansion with existing model-based constraints on GIS expansion, and (ii) use the resulting process knowledge to make initial assessment of implications for near-future GIS melt.

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

Training in all project-specific skills provided by supervisorial team:
- Radiometric Ar-Ar dating (Barfod, NERC NEIF);
- Constructing age model for rock sequence (Jones, Maffione);
- Icesheet processes and vulnerability (Barrand);
- Palaeo-Ice Sheet modelling (Gasson);
- Expert knowledge of Greenland and Iceland ice sheets and Icelandic rock archives (external partners).
Training in more general scientific skills and horizon-broadening activities are available via CENTA.
Public Engagement / Outreach training opportunities:
- External training and mentorship from Hall (Natural England);
- Working with BISCA to publicise ice sheet vulnerability results.

Partners and collaboration

Jon Todd (Natural History Museum) offers specialist knowledge in mollusc systematics and collections that are fundamental to developing the age model for the Tjörnes succession. Dan Barfod (Scottish Environmental Research Centre) is facilitating the radiometric dating. Áslaug Geirstóttir is expert in the Icelandic record of glaciation and will advise on Paper 2. Benjamin Keisling (U. Texas) will provide specialist knowledge of GIS modelling, and Kasia Sliwinska (Geological Survey of Denmark and Greenland) will provide observations and models of the GIS, for Paper 3. Jonathan Hall (Natural England) will contribute public outreach training and external DR mentorship.

Further details

Further details on how to contact the supervisor for this project and how to apply for this project can be found here:

Prospective applicants are positively encouraged to contact Steve Jones ([email protected]), Nick Barrand ([email protected]) or Marco Maffione ([email protected]) in advance of applying to ask questions about the project, discuss whether working with us on this project at the University of Birmingham is a good fit for you, or to ask questions about putting together a strong application. We are also happy to put you in contact with current and former students to ask questions about their experiences.

To apply to this project:

You must include a CENTA studentship application form, downloadable from: CENTA Studentship Application Form 2024.
You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.
Please submit your application and complete the host institution application process via: https://sits.bham.ac.uk/lpages/LES068.htm. Please select the PhD Geography and Environmental Science (CENTA) 2024/25 Apply Now button. The CENTA application form 2024 and CV can be uploaded to the Application Information section of the online form. Please quote CENTA 2024-B23  when completing the application form.

Applications must be submitted by 23:59 GMT on Wednesday 10th January 2024.

Possible timeline

Year 1

Produce draft age model for upper Tjörnes succession. Ice sheet modelling training. Trip to Iceland for field area familiarization and to collect new drone imagery of upper succession, to aid science communication and public outreach.

Year 2

Finish and submit paper 1 (age model). Carry out ice sheet modelling, and produce draft paper 2 on Iceland ice sheet.

Year 3

Finish and submit paper 2. Compare early growth histories of the Iceland and Greenland Ice Sheets, and draft paper 3 on implications for near-future Greenland Ice Sheet melt.