The term “periglacial” refers to the areas adjacent to the margins of glaciers or ice sheets, or areas that experience the effects of freeze-thaw processes associated with cold climates. Periglacial environments are characterized by frozen ground, including permafrost, and a range of landforms and features shaped by the action of freeze-thaw processes, such as frost heaving, frost wedging, solifluction, and patterned ground.
Periglacial features are landforms and structures that result from the freeze-thaw processes that occur in periglacial environments. Some examples of periglacial features include:
- Frost heaving: It occurs when freezing and expansion of water in the ground causes the soil or rocks to heave upwards, resulting in mounds or hummocks on the ground surface.
- Frost wedging: It occurs when water infiltrates cracks in rocks, freezes, and expands, causing the cracks to widen and rocks to break apart.
- Solifluction: It refers to the slow downslope movement of saturated soil or sediment over permafrost or frozen ground, resulting in lobes or terracettes on hillslopes.
- Patterned ground: It refers to the characteristic surface pattern of polygons, circles, or stripes formed by the sorting and movement of soil and rocks due to freeze-thaw processes.
- Pingo: It is a conical or dome-shaped hill made of ice that forms in permafrost regions due to the pressure of groundwater freezing and pushing up the overlying soil and rocks.
Periglacial features are important indicators of past and present periglacial environments and provide insights into the geomorphic processes that shape landscapes in cold climate regions. They are also of significance in various engineering and construction activities in periglacial areas, as they can impact foundation stability, infrastructure development, and land use planning.
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