Submarine drumlins on the continental shelf offshore of NW Ireland

Abstract

Drumlins are streamlined subglacial landforms, usually formed of sediment, that record the former direction of ice-sheet flow across a landscape (Clark et al. 2009). They have been widely observed in a range of glacial environments, both terrestrial and marine. On the continental shelf offshore of NW Ireland multibeam-bathymetric data show elongate landforms with a morphology consistent with published observations of drumlins (Fig. 1). These landforms record the former flow of a terrestrially sourced, grounded Irish Ice Sheet across the continental shelf during the last glaciation (O Cofaigh et al. 2012). Fig. 1. Drumlins on the continental shelf offshore of NW Ireland. Acquisition systems Simrad EM1002S and EM3002 on the Celtic Voyager and EM1002 on the Celtic Explorer . Grid-cell size 20 m. ( a ) Oblique view of the seabed 5 km NW of Tory Island showing a swarm of closely spaced drumlins indicating NW ice-flow. VE×5. ( b ) Close-up of drumlins showing …