The islands have been shaped by numerous glaciations during the Quaternary Period, the most recent being the Devensian.[citation needed] As this ended, the central Irish Sea was deglaciated and the English Channel flooded, with sea levels rising to current levels some 4,000 to 5,000 years ago, leaving the British Isles in their current form. Whether or not there was a land bridge between Great Britain and Ireland at this time is somewhat disputed, though there was certainly a single ice sheet covering the entire sea. COUNT 4
QSN1 What was the most recent glaciation that has shaped the British Isles? ANS1 Devensian QSN2 What happened with the Devensian glaciation ended? ANS2 the English Channel flooded QSN3 When did sea levels reach their current highth? ANS3 4,000 to 5,000 years ago QSN4 What covered the sea between Ireland and Great Britian during the last glacier? ANS4 a single ice sheet