An illustration of what the land bridge connecting Britain to Europe may have looked like, before the formation of the Dover Strait. Image: Imperial College London/Chase Stone
Britain has begun its political divorce from the EU, but new research shows that a geological separation already occurred – 450,000 years ago.
As the post-Brexit atmosphere in the UK remains frosty, researchers have discovered that this separation of Britain from Europe is actually not the first occurrence, geologically speaking.
According to new research from Imperial College London (ICL) and some European colleagues, what we now call the English Channel looked far, far different 450,000 years ago.
In the middle of an ice age, thick ice stretched right across the North Sea, from Britain to Scandinavia, meaning that the area of the English Channel was actually dry land, with a frozen tundra landscape that was criss-crossed by small rivers.
Recent evidence shows that as the ice melted in the following years, Britain began separating from Europe as a result of a huge spillover from a proglacial lake spanning two episodes.
Based on the available data, it is believed that during the first episode, a gradual spillover occurred. By the time the second one arrived, the spill had turned into a disastrous flood.
3D perspective view of bathymetry in the Dover Strait showing a prominent valley in its centre. Image: Imperial College London
‘The Brexit nobody voted for’
10 years ago, ICL researchers discovered the remnants of enormous valleys in the centre of the English Channel.
Their theory suggested the likelihood of a massive flood incident, possibly caused by a catastrophic breach in a chalk-rock ridge joining Britain to France.
Going by this new research, it is believed that the chalk ridge acted as a huge dam – located around the site of the Channel Tunnel today – to the proglacial lake.
To highlight this, the researchers identified several plunge pools from the top of the natural dam to the depths below, estimated to be about 100m high.
The second event, resulting in the massive flood, eventually fully opened the Dover Strait.
“The breaching of this land bridge between Dover and Calais was undeniably one of the most important events in British history, helping to shape our island nation’s identity, even today,” said Prof Sanjeev Gupta, who was involved in the research.
“When the ice age ended and sea levels rose, flooding the valley floor for good, Britain lost its physical connection to the mainland. Without this dramatic breaching, Britain would still be a part of Europe.
“This is Brexit 1.0 – the Brexit nobody voted for.”
