Glacial seismic geomorphology offshore northwest Europe

Plio-Pleistocene records of ice-rafted detritus suggest that northwest European ice sheets regularly advanced across palaeo-coastlines. However, while these records are important, they provide only a limited insight on the frequency, extent, and dynamics of the ice sheets that were delivering the detritus. Three-dimensional reflection seismic data of the northwest European glaciated margin have previously documented buried glacial landforms that inform us on these uncertainties. This work combines existing landform records with new seismic geomorphological observations to catalogue landform occurrence along the European glaciated margin and considers how these features relate to ice sheet history. The compilation shows that Early Pleistocene ice sheets regularly advanced onto and across the continental shelves. This is important because Early Pleistocene sea level reconstructions show lower magnitude fluctuations between glacial-interglacial cycles than when compared to the Middle-Late Pleistocene. The potential for more extensive and more frequent Early Pleistocene glaciation provides a possible mismatch with these sea level reconstructions. This evidence is considered with global records of glaciation to contemplate the possible impacts on our wider understanding of Plio-Pleistocene climate changes, in particular how well Early Pleistocene sea level records capture ice sheet volume changes and how quickly large ice sheets waxed and waned. Resolving such issues relies on how well landforms are dated, whether they can be correlated with other proxy datasets of environmental change, and how accurately these proxies reconstruct the magnitudes of past climatic changes. The results leave many more questions about Pleistocene glaciation in Europe unresolved, with significant impacts on our global understanding of how sea level evolved through the Pleistocene and its association with ice sheet development.