Castlepook’s Deep Winter
This was not yet the Last Glacial Maximum, the later phase in which the British–Irish Ice Sheet expanded to cover Ireland and much of the surrounding continental shelf. Yet neither was the island simply free of ice. Research increasingly indicates that the British–Irish Ice Sheet had a long and dynamic history, with growth, retreat and renewed advances before its maximum extent. The precise position of ice margins around 33.8 thousand cal BP remains uncertain, and may have differed sharply from one region to another. It is unsafe to imagine a single uniform map for the entire island.