Objectives
1. To collect new geophysical and sea bed sediment cores from six field sites in the Irish Sea region in order to reconstruct the depth and timing of the Late Glacial relative sea level (RSL) lowstand along an isostatic gradient between the Last Glacial Maximum (LGM) ice limit and the former ice centre in SW Scotland. This will significantly extend the observational record of RSL in the British Isles and enhance existing RSL curves that are currently largely based on Holocene data and comparatively shallow depths. The last marine-based campaign of this type was completed in the North Sea basin under the NERC Land Ocean Interaction Project in the mid 1990s. No equivalent effort has thus far been directed to the Irish Sea basin.
2. To test and improve existing models of glacio-isostatic rebound and associated RSL change in the Irish Sea basin. Existing models predict different RSL curves that have varying levels of agreement with field observations of RSL data. The most crucial area in which data are lacking is the Late Glacial lowstand and during this interval a paucity of field data mean model differences cannot be resolved. We will compare our our newly acquired RSL data to existing model simulations and re-run the BIM-1 model to minimise discrepancies with field data. Improving these models is important since they enable us to reconstruct former ice sheet loading scenarios and help establish key parameters of earth rheology (lithospheric thickness and mantle viscosity).
3. To use our newly aquired RSL observations and seabed bathymetry to produce new palaeogeographic reconstructions of the evolution of the Irish Sea Basin from the LGM through to the mid Holocene. These maps, constructed at 1000 year intervals, will enable us to test long-standanding debates regarding the insularity of Ireland, human migration, palaeoecology and palaeo-oceanography in the region.