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Pingo National Landmark is a natural area protecting eight pingos near Tuktoyaktuk, Northwest Territories. It is in a coastal region of the Arctic Ocean which contains approximately 1,350 Arctic ice dome hills—approximately one quarter of the world's pingos. The Landmark comprises an area roughly , just west of Tuktoyaktuk, and includes Ibyuk Pingo—Canada's highest, exceeded in height only by Kadleroshilik Pingo in Alaska—at .〔 The Landmark, which lies within the Inuvialuit Settlement Region, is managed by Parks Canada under the National Parks Act. Although a nationwide landmarks program was envisioned at its creation, Pingo remains the country's only National Landmark. In a region near the Beaufort Sea which is quite flat, pingos dominate the skyline, rising from , in various stages of growth and collapse. Ibyuk Pingo, the highest, continues to grow about per year, and is estimated to be at least 1,000 years old. Unique to areas of permafrost, pingos have formed here thanks to numerous lakes in the Tuktoyaktuk Peninsula. ==Other features== Besides pingos, the Landmark contains an excellent example of massive ice. One section of the frozen groundwater, part of an eroded hillside by the sea, is over long, and high. Other less visible ice beds in the region are over thick. This type of ice is found in permafrost, and can be thousands of years old. Other features of a permafrost environment can be found in the Landmark, including wedge ice. These are vertical masses of ice that form after water freezes in the cracks around ground that has contracted due to extreme cold. When ice wedges connect to one another, they can form tundra polygons, which are also visible at Pingo National Landmark. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pingo National Landmark」の詳細全文を読む スポンサード リンク
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