Scientists from the British Antarctic Survey (BAS) have identified deep scraping marks in the North Sea left by giant tabular icebergs that moved through the area between 18,000 and 20,000 years ago.
This finding is the first clear evidence that gigantic ice blocks floated less than 145 kilometers from the current British coast and provides key insights into climate change and the evolution of the Antarctic ice sheet.
The Last Glaciation and the Movement of Giant Icebergs
The marks were detected in sediments buried beneath the seabed, corresponding to the period of the last glaciation, when a huge ice sheet covered the British Isles and began to retreat due to global warming.
This phenomenon was identified in the Witch Ground Basin, between Scotland and Norway, thanks to seismic data used to locate drilling platforms.
The Impact on Ecosystem and Climate Change
Tabular icebergs come from ice shelves, which are the floating fronts of glaciers. Their detachment is a natural phenomenon, but the accelerated disintegration of these structures can lead to a collapse of the ice sheet, as happened with the Larsen B ice shelf in 2002.
In that case, the increase in air temperature caused a massive fracture in just one week, accelerating the release of glaciers and contributing to the rise in sea level.
Lessons for the Antarctic Ice Sheet
Studying the ancient iceberg marks in the North Sea allows us to understand the processes of ice shelf break-up and its consequences.
According to experts, if a similar transition is recorded in Antarctica</strong — from the detachment of large tabular icebergs to the formation of smaller and numerous blocks — it could mean that the continent is at risk of significant and rapid mass loss.
An Ongoing Mystery: Causes of the Collapse
It is still unresolved whether the accelerated retreat of the British ice sheet was a consequence of the collapse of its ice shelves or if the fragmentation was a sign that mass loss was already underway.
Better dating of sediments could provide key answers about the ice dynamics in the modern era and its implications for climate change.
