According to a recent study, a hidden valley buried beneath the ocean floor in the north sea was quickly craved out around the 'death throes' of an ancient ice sheet near the end of the ice age about 20,000 years ago.
Subterranean structures can give clues about the mode of ice sheet reaction towards climate change.
The enormous underground ravines, referred to as tunnel valleys, were carved into the ancient seafloor by meltwater that flowed into channels beneath the ice sheets.
Deep canyons were carved into the seafloor by the fast-moving water's massive weight of the ice blocks, which has since been covered by hundreds of metres of silt deposition.
British Antarctic Survey (BAS) geologists mapped out the network of tunnel valleys in the North Sea, which was formerly covered in an ice sheet and was also part of a capped part of continental land.
These results were published in September 2021 in the journal Geology. The researchers used a 3D seismic reflection technology that emits sound waves to discover buried canyons, some of which date back around two million years.
In the most recent study, published Oct. 5 in the journal Quaternary Science, researchers determined exactly how some of the tunnel valleys were born. The results showed that the tunnels were likely carved out over the span of a few centuries, which is much faster than the team had initially anticipated.
According to a media outlet, James Kirkham, a doctoral candidate with BAS, said, "This is an exciting discovery." "We know that these spectacular valleys are carved out during the death throes of ice sheets." "We have learned that tunnel valleys can be eroded rapidly beneath ice sheets experiencing extreme warmth."
The researchers had known about similar tunnel valleys for decades, but until now, the creation of these channels has been a mystery.
The theory contends that the canals prevented liquid from accumulating on top of or underneath the ice and, as a result, inhibited further ice from melting by draining meltwater away from the ice sheets.
