Research has revealed that the British Isles repeatedly submerged under a layer of ice that extends to the center of the North Sea more than a million years earlier than previously thought.
A team led by scientists from the University of Manchester and the University of Aberdeen analyzed the sediment and seismic data from the depths of the North Sea and discovered that extensive ice sheets covered much of the United Kingdom and Ireland since 2.5 million years.
At the same time, an even larger ice sheet covered much of Scandinavia. At that time, the North Sea was narrower and deeper than it is today, like a great "fjord". Periodically, the ice sheets of the British Isles and Scandinavia advanced to depths of approximately 250 m and generated icebergs of almost 300 m in height.
1.9 million years ago the two layers of ice merged repeatedly in the center of the North Sea, filling the "fjord", as they advanced and retreated in response to climatic changes controlled by Earth's orbit.
So far, the scientific consensus has been that glaciation on this scale occurred for the first time in the North Sea about 1.1 million years ago.
However, the new research, which has been published in the journal Science Advances shows that it happened for the first time 1.4 million years ago. This marks a significant advance in our understanding of the extent of the glaciation of the past in northwestern Europe.
The study was carried out by geoscientists from the universities of Aberdeen, Manchester, Sheffield and Queen's University Belfast, Apache North Sea Ltd., RPS Ichron, Mærsk Olie og Gas and Lloyds Register.
The research required a multidisciplinary approach and Dr. Rachel Harding, a researcher at the University of Manchester, said: "The North Sea basin has been declining for millions of years, continuously preserving layer after layer of evidence of layers of past ice, whose evidence is not available on land, using geophysical data, then we search these different layers for traces of layers of ice that disappeared long ago. "
Dr. Andrew Newton, of the Queen's University Belfast and visiting researcher at the University of Manchester, co-directed the project with Dr. Brice Rea of the University of Aberdeen. Dr. Newton said: "From these results we discovered that if you visited the North Sea 2.5 million years ago, Britain would be under a layer of ice and you would have seen huge icebergs floating around the North Sea and so south as the coast of the Netherlands. "
Professor Mads Huuse, also from the School of Earth and Environmental Sciences of the University, continued:" This work has completely rewritten our understanding of the glacial history of the North Sea. and has shown that large ice sheets have frequently covered the British Isles for 2.5 million years, then, approximately 1.9 million years ago, the British and Scandinavian ice sheets often merged in the middle of the Sea. from the North through different ages of ice, covering much of northwestern Europe under a layer of ice "
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Extensive layers of sea-terminated ice in Europe for 2.5 million years. Science Advances (2018) DOI: 10.1126 / sciadv.aar8327