How does wedge ice differ from pingo ice?

In the study of permafrost, wedge ice and pingo ice differ significantly in their formation processes, physical structure, and geometry:

• Formation: Wedge ice forms through the thermal contraction of frozen ground during extremely cold winters, which creates vertical cracks that fill with meltwater in the spring. In contrast, pingo ice originates from groundwater under hydrostatic pressure, which pushes upward to form a lens-shaped ice body.1234
• Structure and Shape: Wedge ice is characterized by vertical or inclined, foliated sheets that often form part of a polygonal network in the ground. Pingo ice typically exists as a massive, clear, lens-shaped core that pushes overlying material upward to create a dome-shaped hill known as a pingo.543
• Distribution: While ice wedges are often found in polygonal patterns across the landscape, pingos are distinct, isolated conical mounds that can reach up to 90 metres in height.13

These two forms represent distinct types of ground ice, with wedge ice being a product of surface-level thermal stress and pingo ice resulting from subsurface hydraulic pressure.24