Doggerland was an area of land, now submerged beneath the southern North Sea, that connected Britain to continental Europe. Over time, the area was flooded by rising sea levels after the last glacial period around 6500–6200.
The existence of Doggerland was first suggested in a late 19th century book “A Story of the Stone Age” by H.G. Wells, set in a prehistoric region where one might have walked dryshod from Europe to Britain.
The landscape was a diverse mix of gentle hills, marshes, wooded valleys and swamps. Geological surveys have suggested that it stretched from where Britain’s east coast now is to the present-day Netherlands, western coast of Germany, and peninsula of Jutland.
It was probably a rich habitat with human habitation in the Mesolithic period, although rising sea levels gradually reduced it to low-lying islands before its final submergence, possibly following a tsunami caused by the Storegga Slide.
Mesolithic people took advantage of Doggerland’s rich migrating wildlife and seasonal hunting grounds that has been evident in the ancient bones and tools embedded on the present sea floor brought to the surface by fishing trawlers.
A recent hypothesis postulates that much of the remaining coastal land was flooded by a megatsunami around 6200 BC, caused by a submarine landslide off the coast of Norway known as the Storegga Slide.
This suggests: “that the Storegga Slide tsunami would have had a catastrophic impact on the contemporary coastal Mesolithic population…. Britain finally became separated from the continent and in cultural terms, the Mesolithic there goes its own way.”
Another view speculates that the Storegga tsunami devastated Doggerland but then ebbed back into the sea, and that later Lake Agassiz (in North America) burst releasing so much fresh water that sea levels over about two years rose to flood much of Doggerland and make Britain an island.