Cryosol | Soil Monoliths Cryosols (or Gelisols in USDA Soil Taxonomy) have permafrost either within 1 m of the surface or within 2 m if the pedon is strongly cryoturbated in the active layer. Monoliths.soilweb.ca
Among the ancient Greeks, Homer thought the world to be flat. In contrast, Pythagoras postulated that the earth was round. A century later, Aristotle sided with the theory of the roundness of the earth.
Greek evidence for the Earth's shape and spin. A round Earth. Pythagoras' pupils, if not the great man himself, knew that the Earth is round. Traveller's tales of ships disappearing over the horizon and the Pole Star shifting to a higher position in the sky as one journeyed north suggested a curved Earth.