The repeated annual freezing and thawing of permafrost soils can produce very interesting geometric features called patterned ground. These include polygons, circles, nets, steps, and stripes. They typically occur in periglacial regions such as those in Siberia, Canada, Alaska, Iceland, Greenland, Antarctica and the Andes. The actual process by which these patterns form had long puzzled scientists but the introduction of computer-generated geological models in the past 20 years has allowed scientists to relate the formation of these features to phenomena associated with frost heaving, which refers to expansion that occurs when wet, fine-grained, and porous soils freeze.
Read more »
© Amusing Planet, 2015.