Discovery of a surprising process at the origin of the valleys of the ice age!
Researchers have recently discovered that the ancient valleys were formed by carrying abundant melt water under the ice towards the sea, in just a few hundred years. Thousands of valleys are located in the ocean floor of the North Sea. This process would have prevented the old layers of ice that covered the United Kingdom and Europe to fall apart.
This new study, published in the journal Quaternary Science Reviews, clarified what happened during the melting of these vast layers of ice, 20,000 years ago. According to the researchers, this could shed light on how glaciers can react to global warming today.
The ancient valleys formed at an astonishing speed
Tunnel valleys are huge channels that can reach 150 km long, 6 km wide and 500 m deep. They allow to drain water under the layers of ice in fusion. By using techniques ofsubsurface imaging technology and a computer model, the team discovered that these valleys could grow faster under the influence of intense heat.
Based on the evidence collected in the valleys, they performed a series computer models, simulating the development of valleys. They wanted to check the rate of formation of the last layer of ice covering the United Kingdom at the end of the ice age.
Research has revealed that the process is rather rapid on the scale of geological time. The huge tunnel valleys were formed over a few hundred years. Moreover, by expelling the water, they slowed the rates of ice loss.
Will these tunnel valleys stabilize ice loss?
If the drainage of water under the ice caps actually stabilizes the flow of ice, then it will prevent today’s ice caps from collapsing in extreme heat. However, detailed seismic scans revealed a motion of ice that is both stagnant and rapid in the valleys. This makes it uncertain how these channels would act on the ice sheet.
Climate change is affecting the glaciers of Greenland and Antarctica faster than before. It is therefore imperative that scientists consider the effects of the rapid formation of these tunnels in the evolution models of the ice caps in the years to come.
It is unclear whether these channels will stabilize or destabilize contemporary ice sheets under warming conditions. It is therefore necessary to perform new research to find out how these tunneled valleys can help stop the loss of ice.