Arctic pingos. Photo by our reporter Feng Weidong
In March, the Arctic remains an icy and snowy world with biting winds, showing no signs of spring’s arrival.
The rental car carrying the reporting group sped along the vast Ice Road when suddenly clusters of white mounds came into view. Round or elongated, large or small, they were scattered across the wilderness. These snow-covered mounds are a unique Arctic permafrost landform—pingos.
According to staff from Parks Canada, the word "pingo" derives from the Inuit term “Pingu,” meaning small hill. Over 700 years ago, Inuit hunters used pingos as high points to scout for wildlife on the tundra and whales in nearby waters. They also served as burial mounds and lookout spots to observe people arriving in the area. The vast tundra of Canada’s North is dotted with these mysterious mounds.
Canada’s Tuktoyaktuk Peninsula has numerous lakes, most of which are too deep to fully freeze in winter, providing ideal natural conditions for pingo formation. In this region, lakes deeper than two meters typically do not freeze completely during the winter. John Ross Mackay, known as the father of permafrost research in Canada and a professor in the Department of Geography at the University of British Columbia, conducted years of research on pingo formation. His findings revealed that sand-filled depressions or lake bottoms generate water expulsion during bidirectional freezing. Due to the closed nature of the system, the expelled water is under high pressure. This pressure far exceeds the weight and freezing forces applied by the overlying layers, causing the ground to rise. The water expulsion also supplies water for the formation of large ice cores, whose growth exerts strong upward frost heave forces. These forces compress the surrounding soil, pushing the ground upward and forming pingos.
Established in 1984, the Pingo Canadian Landmark protects eight pingos within an area of 16 square kilometers near Tuktoyaktuk, including the world’s second-largest, Ibyuk Pingo. Standing 50 meters tall and 300 meters in diameter, Ibyuk is over 1,000 years old and continues to grow at a rate of 2 centimeters per year. It is the world’s oldest and one-of-a-kind “living pingo,” serving not only as a landmark of the Arctic Circle but also as the northernmost point in Canadian territory. The entire Mackenzie River Delta in Canada is home to about 1,350 active pingos of various sizes, accounting for nearly a quarter of all pingos in the world.
This unique Arctic landform has brought significant economic benefits to residents of Canada’s Northwest Territories, attracting large numbers of tourists from around the world every year. The all-weather Inuvik-Tuktoyaktuk Highway, expected to be completed in 2017, will bring even more visitors to the region. However, while enthusiastically promoting pingo tourism, Ms. Jennifer from Parks Canada also expressed concern about the impact of global warming on pingos. She said climate change is creating risks of melting and collapse for Arctic pingos.
In interviews, local indigenous people expressed general caution about the government’s aggressive push to develop mineral and tourism resources. They hold deep reverence for the land their ancestors have lived on for generations and worry that increased human activity in the Arctic will gradually erode the natural environment. As the Canadian government advances its Arctic strategy, the once remote and untouched Arctic is becoming more accessible. Striking a balance between potential environmental risks in the Arctic and the economic development opportunities it presents is a concern lingering in the minds of people in Canada’s Northwest Territories.