Mathieu J. Duchesne, geoscience researcher at the Geological Survey of Canada, emphasizes from the outset that his organization has been interested in underwater permafrost since the 1970s. However, since 2010, the first high-resolution maps have revealed huge depressions in the seabed off the coast of the Northwest Territories.
“It was quite surprising! We, at the beginning, immediately associated this with the degradation of underwater permafrost.”
This permafrost was formed when the continental shelf was exposed to the extreme conditions of the Arctic, a million years ago, explains Mr. Duchesne. He specifies that with the rise in sea levels, the permafrost began to degrade, which at the same time reduced the bearing capacity of the ice, which, by disappearing, caused the seabed to subside.
Under the influence of climate change, particularly the warming of the oceans, this phenomenon has accelerated, according to the researcher.
“After we noticed the formation of these depressions, in 2022, we carried out another mission, aboard a Korean icebreaker and we deployed all kinds of technological tools, including an underwater vehicle. remote-controlled sailor which allowed us to see what these depressions consisted of, therefore by filming in real time what we could observe.
It was at this moment that we saw these layers of almost pure ice which were exposed on the sides of one of these subsidences.
– Mathieu J. Duchesne, geoscience researcher
Samples were taken as part of this research project carried out within an international consortium. Questions remain to be clarified, namely the extent of these depressions and when these layers of ice were in place.
Mr. Duchesne discusses the implications of this discovery and future research steps.
Panorama
To listen to the interview with Mathieu J. Duchesne, click here.
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