Reconstructing the configuration of the British/Irish Ice Sheet off the north west coast of Ireland

Evidence from the terrestrial glacial record indicates that the limits of the last British/Irish Ice Sheet must have extended far out onto the continental shelf in the Northwest of Ireland. Data from the Irish National Seabed Survey (INSS) provides the first real opportunity to investigate this hypothesis in detail. This study utilised INSS multibeam swath bathymetry imagery along with backscatter and acoustic sub-bottom data sets to investigate the glacial record on the continental shelf off the North West coast of Ireland. The main objective was to determine whether the last British/Irish ice sheet occupied the shelf, and if so, to reconstruct its configuration and extent. The results show a complex seafloor morphology comprising of both relict and modern bedforms and we present the first evidence of former glaciation in the region. A range of submerged glacial landforms and sediments are evident that are most likely associated with a Scottish ice mass that invaded this portion of the continental shelf. The configuration of landforms close to the shelf edge suggests that ice extended as far as this and then rapidly ablated. The results provide the first evidence of at least one widespread shelf glaciation in the area and constrain ice sheet
extent in this region.