Two great floods

The Pas de Calais Strait was washed out by glacial floods

The British, who are proud of their status as islanders and speak somewhat condescendingly of the rest of the Europeans who have to live on the continent, should be grateful for the terrible prehistoric flood. Several hundred thousand years ago, a strong current literally washed out the Pas de Calais Strait, cutting off Great Britain from the mainland. This hypothesis was put forward by a group of scientists led by Sandiv Gupta from Imperial College London, writes the journal Nature.

To prove this idea, Gupta and his colleagues mapped the bottom of the Pas de Calais, using data from the British Hydrographic Office and refining them using echo sounders. According to scientists, the resulting profile of the strait's bed with all the underwater pools and shoals suggests that a catastrophic flow once swept through this area. A similar thing happened 15 thousand years ago in America with Lake Missoula in the northwestern United States. The breakthrough of the banks of this reservoir and the subsequent flood created a very characteristic topography. The British saw something similar at the bottom of their strait.

According to the hypothesis of Sandiv Gupta's group, 450 thousand years ago Great Britain was connected to Eurasia in the area of ​​​​present-day Dover by a chain of limestone hills. And to the northeast of this isthmus a lake formed, filled with water from melting glaciers - the prototype of the present North Sea. Here it should be recalled that over the past several hundred thousand years, the Northern Hemisphere of the Earth has repeatedly gone through climatic cycles of warming and cooling. As temperatures dropped, glaciers from the Scandinavian mountains moved south and covered northern Europe. When the climate softened, they melted and created rivers and lakes that greatly changed the topography of the continent.

Something similar happened 425 thousand years ago, only the scale of this melting was more reminiscent of a regional catastrophe. The glacier was receding, the water in the lake was rising and finally overflowed over the chain of hills. The flow, apparently, was small at first, but soon turned into a waterfall of cyclopean proportions: according to scientists, a million cubic meters of water poured out of the lake per second. It was he who paved the way for the future Pas de Calais. But this was not the last flood: history repeated itself about 200 thousand years ago, during the next glacier retreat, and then the flood was even more powerful. After this, apparently, the strait between Great Britain and continental Europe acquired its current shape, and Albion finally became an island.

Mikhail MANSKOY