These rock polygons (approximately 2m in diameter) were formed by the repeated freezing and thawing of groundwater. The freeze thaw action forces larg
These rock polygons (approximately 2m in diameter) were formed by the repeated freezing and thawing of groundwater. The freeze thaw action forces larger stones toward the surface as smaller soils flow and settle underneath larger stones . At the surface, areas that are rich in larger stones contain much less water than highly porous areas of finer grained sediments. These water saturated areas of finer sediments have a much greater ability to expand and contract as freezing and thawing occur, leading to lateral forces which ultimately pile larger stones into clusters and stripes. Through time, repeated freeze-thaw cycles smooth out irregularities and odd-shaped piles to form the common polygons, circular, and stripes of patterned ground. Photographed in
Size: 5173px × 3449px
Photo credit: © PETER J. RAYMOND/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No
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