PhD in Geography

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. One way to address this concern is 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. Instead, this PhD project will get an answer much more quickly 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.