A new study has shown that hidden valleys under the North Sea ocean bottom were quickly created during the “deaththroes” of an old ice sheet towards the end the last ice age, which occurred around 20,000 year ago.
These subterranean structures may provide clues to the future of modern ice sheets in response to rapid warming. Climate changeResearchers agree.
Tunnel valleys are large underground structures that have been carved into the seafloor by melting ice water.
Due to the immense weight of rapidly melting slabs ice, the water flow created deep canyons in the seafloor. These channels were later covered by hundreds of meters worth of sediment.
Tunnel valleys can reach lengths of up to 93 mi (150 km), width of 3.7 mi (6 km), and depth of 1,640 feet (500m). According to a study, Statement from researchers.
British Antarctic Survey (BAS), which is a research organization, mapped out the North Sea tunnel valley network in 2021. The North Sea was once covered by an ice sheet that also capped parts Europe and the UK during Europe’s last Ice Age, 126,000 to 12,000 Years ago.
The team discovered thousands of buried canyons using 3D seismic reflection technology. This emits sound waves to search for structures under the seafloor. Some of these canyons date back more than 2 million years. These results were published in the journal Science in September 2021. Geology.
The new study was published in the journal on Oct. 5. Quaternary Science ReviewsThe same researchers combined the canyon maps with computer models to determine how many tunnel valleys were created.
The team discovered that the tunnels were likely to have been carved in a matter of centuries. This is faster than they had originally thought.
Related: Scientists have jumped for joy at the discovery of Antarctica’s hidden world.
This is an exciting discovery. According to the statement, James Kirkham (a doctoral candidate at BAS), the study’s lead author, we know these valleys were formed during the death throes ice sheets.”
“We found that tunnel valleys can be rapidly eroded under extreme heat-sensitive ice sheets.”
Although scientists have known for decades about tunnel valleys similar to those found in the Alps, until now the mystery surrounding their creation has remained.
Kelly Hogan (a marine geophysicist from BAS) said, “We have been watching these huge meltwater streams from areas covered in ice sheets in the past for over a hundred years, but we didn’t really understand how it formed.” The statement contains these words.
Tunnel valleys develop when meltwater runs through vertical cracks of ice and into a meltwater stream below the ice. The meltwater flow channels liquid like a huge “plumbing” system, researchers say. In the paper.
Valley formation is seasonal. The result is that valleys form during the summer, when there is more melting, which temporarily speeds up valley growth.
The tunnel valleys may form at the end of an ice sheets’ life. However, the study authors believe that this drainage system may actually slow down the rate of ice melting and could have extended the life span for the North Sea icesheet.
This hypothesis states that by draining meltwater from the ice sheets the channels prevented liquid from pooling above or below the surface of the ice. It also prevents more ice melting.
Researchers are not sure how fast the ice sheet was melting at this stage. There was evidence of limited movement in tunnel valleys, which suggests that these valleys are slowing down the rate at which ice is losing.
Others, however, showed evidence of rapid retreat which could indicate that valleys had the opposite effect of increasing ice loss rate according to the statement.
Therefore, scientists will continue to investigate the tunnel valleys in order to determine how meltwater channels might affect ice loss rates.
“The critical question now is whether this extra meltwater flowing in channels will cause our sea ice sheets flow more quickly or slower into water?” Hogan .
This question can be crucial in accurately predicting the future of modern ice sheets like those found in AntarcticaGreenland, and will be affected by Climate changeThe researchers agreed.
The current models used to predict the rate of ice losses in these regions don’t take into account tunnel valleys. Researchers are missing a crucial piece of information.
Researchers wrote that if new tunnel valleys form or “switch onto” below the current ice sheets, it could dramatically change how fast they melt. This is especially true since these structures only take a few hundred year to form.
Kirkham said, “The rate at which these enormous channels can form means that it is an important, but currently ignored mechanism.” .
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This article was originally published in Live Science. Learn more Original article available here.
