Final answer:
Ice wedges are formed through repeated freeze-thaw cycles that cause ground contraction and cracking, followed by water seeping into the cracks and freezing. The rate of growth can be a few centimeters per year, depending on climatic conditions.
Step-by-step explanation:
Ice wedges are believed to be formed in regions with cold climates through a process known as ice wedge polygenesis.
The process begins when temperatures drop, causing the ground to contract and crack. Water from snowmelt or rain seeps into these cracks, and as temperatures plunge again, this water freezes and expands.
Over time, repeated freeze-thaw cycles allow these ice wedges to grow incrementally as more water enters and freezes in the cracks. The rate of growth for ice wedges varies depending on climatic conditions; however, in general, ice wedges can grow a few centimeters per year.