The frequency of landslides on the Canadian Arctic island Banks has increased 60 times in the last half century. This makes them one of the most dangerous consequences of global warming, scientists write in the journal Nature Communications.
“If the permafrost has already melted, we can’t stop this slow creep of the soil. We can only hope that such problems will attract the attention of politicians and lead to a decrease in greenhouse gas emissions,” said Antoni Lewkowicz of the university. Ottawa (Canada).
In recent years, climatologists have seriously worried that the warming of the Arctic will lead to the rapid disappearance of all permafrost reserves that have arisen in the soil of Siberia, Alaska and the polar regions of Canada during the last glaciation. According to current forecasts, about a third of the permafrost in the southern regions of Siberia and Alaska will disappear by the end of this century.
Thawing of permafrost, as scientists believe today, will release a huge amount of organic matter, frozen into the soil and accumulated there during millions of years of glaciation. These plant and animal remains will begin to rot, releasing methane and carbon dioxide into the atmosphere, as well as burning during natural fires, which will further accelerate global warming.
In addition to nature, these catastrophic processes will have a very negative impact on the inhabitants of the polar region. Recently, Russian and foreign climatologists have found that melting of permafrost will affect over 70% of the infrastructure in the polar cities of Russia, Canada and the United States, and these processes can no longer be stopped regardless of the future Paris Agreements.
Levkovich and his colleague Robert Way (Robert Way) found out that the authors of these forecasts seriously underestimated the scale of one of the phenomena associated with the melting of permafrost – the classic “fast” landslides and slower creeping and subsidence of loose soil.
They came to this conclusion by analyzing high-quality images of the surface of Banks Island, located off the coast of the Beaufort Sea in northwestern Canada, taken by various climate satellites between 1984 and 2016.
Using these images, scientists have calculated the number of mud avalanches, mudflows, landslides and other phenomena associated with the movement of the soil, calculated the area of the affected territory and compared these data with what temperatures prevailed on the Canadian Archipelago in different seasons.
In 1984, as Levkovich notes, their number was relatively small. In total, scientists have counted 84 ground areas affected by landslides. Their area was relatively small and they were all located near the sea in the southern part of the island.
After 30 years, the situation has changed dramatically – the number of landslides has increased 60 times, and many of these mudflows have been slowly moving on the surface of Banks Island for two or even three decades.
Most importantly, the lion’s share of these hotbeds of instability appeared in those years when summer was especially hot. This was typical, for example, for 2010–2012, when temperatures in the American Arctic were above 9 degrees Celsius above the norm in the spring and summer months.
Landslides, avalanches and other manifestations of this phenomenon have already begun to interfere with the life of the Inuit tribe inhabiting Banks Island, littering the rivers and lakes, and also creating obstacles for movement across its territory. Recently, as locals reported to scientists, they began to appear not only in coastal regions, but also in the central regions of this piece of land.
In the future, the number of landslides, as scientists predict, will be even three times higher, which will create problems not only for people, but also for local flora and fauna. In the near future, climatologists plan to begin observing how the damming and pollution of rivers affects the lives of local fish and invertebrate creatures.