An international team of scientists unveiled exceptionally well-preserved glacial landforms buried nearly one kilometer beneath the North Sea, dating back approximately one million years.
Researchers used 3D seismic technology, originally developed to assess sediment suitability for oil, gas, and renewable energy infrastructure, to uncover these ancient features. The technology revealed a landscape etched by a vast ice sheet that once extended from Norway toward the British Isles. The seismic data also uncovered elongated furrows incised into the former seabed by powerful ocean currents predating the ice sheet's advance, suggesting a dynamic marine environment.
"To fully understand the links between glaciers and climate, it is essential to study how past glaciers reacted to long-term climate changes," said Dr. Christine Batchelor, a senior lecturer in physical geography at Newcastle University who helped map and interpret the landforms discovered in the North Sea.
"These 3D seismic data allow us to examine the landscapes buried under the North Sea sediment in astonishing detail," said lead author Dr. Dag Ottesen from the Geological Survey of Norway. He added, "With our high-resolution data, we can see that the shape and size of the furrows is consistent with an origin as ocean current furrows."
The research team identified glacial landforms, including streamlined ridges carved by ice movement and features marking the ice sheet's retreat. They also found that strong ocean currents dominated the North Sea region before ice sheets took hold around one million years ago, shaping the seabed and creating elongated furrows.
According to the researchers, modern seismic data suggest that ice sheets in northwest Europe expanded significantly in response to climate cooling about one million years ago. This discovery aligns with a period of global cooling known as the Mid-Pleistocene Transition, a time that reshaped climate patterns worldwide.
Understanding how past ice sheets responded to climatic shifts can help make better predictions about how today's ice sheets will respond to climate warming. "The next step is to acquire long sediment cores that can allow researchers to better understand the timing of glacial events," Dr. Batchelor said. The research team acknowledges that a limitation of the study is a lack of data about the precise age of the landforms.
"Taken together, these results rewrite our ideas of the glacial history of the North Sea," Dr. Ottesen stated.
Identifying ancient glacial landforms has historically been difficult due to their burial under thick sediment layers.
Other co-authors of the study include Helge Løseth at Equinor ASA, Trondheim, and Harald Brunstad at Aker BP ASA, Trondheim. The findings were published in the journal Science Advances.
The article was written with the assistance of a news analysis system.