Paleo-Europe

Doggerland: the land that drowned

The bottom of the North Sea, from 20,000 years ago until the sea covered it, in 35 seconds.

What you are seeing

20,000 years ago global sea level stood about 120 m lower than today (Spratt & Lisiecki sea-level stack: 117.6 ± 10.1 m lower, 1σ). Ice covered Scotland, Scandinavia and the northern North Sea.

In several reconstructions of the last glacial maximum, British and Fennoscandian ice met across the North Sea and dammed a large lake in its southern part (Sejrup et al. 2016; Hjelstuen et al. 2018); the outline drawn here is the ZBSA EPHA map's digitisation of Sejrup et al.'s Fig. 3A.

The lake is a reconstruction whose existence has been debated, and studies date its end differently — from a possible outburst around 22-21 thousand years ago (Roberts et al. 2018) to 18.7 thousand years ago, when it drained north between the parting ice sheets (Hjelstuen et al. 2018).

The film opens low over the southern North Sea. The caption “This is the bottom of the North Sea” names the place, not dry land: part of it is drawn under the reconstructed lake. After the lake, the southern North Sea is a dry plain in this model, Doggerland, joining Britain to the continent.

As the ice melts the sea comes back, first from the north, then through the Strait of Dover, which in this model floods between 11,500 and 10,000 years ago. The last land link between Britain and the continent breaks between 9,500 and 9,000 years ago. Published reconstructions put the loss of that link between 9,250 and 7,500 years ago.

What is left is an island over today's Dogger Bank, about 12,400 km² when it is cut off. In this model it stays the biggest island in the North Sea, at least 3 times larger than any other, until 7,500 years ago.

Its end has three dates, and they differ. On the model's water map its last dry ground is seen 7,000 years ago and is gone by 6,500. The rendered frames decide land and water pixel by pixel on the terrain, finer than the water map's cells, so a small patch inside the island's outline stays above water longer; the caption gives the first step at which none is left on screen, 5,500 years ago. Published estimates for its end are earlier: from about 8,200 years ago, which one study raises as a possibility (Emery et al. 2019), to about 7,000 years ago at the latest (Walker et al. 2020). The model's end is later than all of them; see the limits below.

The dotted line at the end is the coast of 9,500 years ago, the last time Britain was joined to the continent in this model, drawn over today's sea.

The sea-level gauge and the coastlines

The gauge shows global mean sea level from the Spratt & Lisiecki stack. The coastlines come from a glacial isostatic adjustment model, in which the land itself was still rising and sinking as the ice sheets melted, so around the North Sea the local sea level differed from the global mean. The coast in a frame therefore does not follow the depth contour the gauge reads.

How it was made

Modern bare-earth elevation and bathymetry are shifted epoch by epoch with a glacial isostatic adjustment model, flooded to that epoch's sea surface and overlaid with the modelled ice extent. Every frame is rendered by the Paleo-Europe viewer. The island is measured on the model's own water map: its outline is the dry ground around Dogger Bank on the epoch Britain separates, and it is compared with every other island of the North Sea on each epoch after that.

Limits of the model

The interactive viewer is in private preview.

Video licence: CC BY-NC-SA 4.0, because it is derived from FABDEM. Share it with a link to this page; no commercial use.

Sources

Palaeo-rivers and lakes

Dataset 20260926104933