Pingoilla

Pingoilla are a type of geological formation found in periglacial environments. They are essentially ice-cored hills that can range in size from a few meters to over 70 meters in height and up to 500 meters in diameter. Pingoilla are characterized by a conical or domed shape with a bulge in the center, often containing a crater or depression that may fill with water.

The formation of pingoilla is a process that occurs in areas with continuous permafrost. There are two main types of pingoilla: closed-system pingoilla and open-system pingoilla. Closed-system pingoilla form in poorly drained, flat areas where groundwater, rich in dissolved salts, is trapped beneath the permafrost. As temperatures drop, this water freezes from the bottom up, pushing the overlying soil and sediment into a mound. Open-system pingoilla, on the other hand, develop in areas with discontinuous permafrost and can form in sloping terrain. In these cases, hydrostatic pressure from unfrozen water below the permafrost forces water upwards, where it freezes and causes the ground to bulge.

Over time, the ice core within a pingoilla can melt, leading to the collapse of the overlying soil and the formation of a characteristic circular depression or lake. Pingoilla are found in various Arctic and subarctic regions, including Alaska, Canada, Siberia, and Greenland. They are considered important indicators of permafrost conditions and can provide insights into past climatic changes.