Sand blast sculpturing is a common process, leaving odd-shaped forms that in space imagery really stands out. Consider this Landsat image of the Tanezrouft Basin of southern Algeria. The Sahara, of which this a part, is mainly rocky rather than sandy in cover. Here sculpturing has carved out deflation basins within horizontal to gently dipping sedimentary rocks. Patterns that tend towards circular are the mark of this kind of terrain, but on the ground the effect would probably go unnoticed.
Ice can cover nearly an entire continent, such as Antarctica, or a huge island such as Greenland.
When ice begins to flow by gravity to lower elevations, usually along distinct, often narrow paths, it becomes a glacier. Areas in yellow-orange are vegetated, while reds associate with basaltic rocks and sparse vegetation. Green in the ocean is sediment, and black around the ice cap is a zone of ground soaking from glacial meltwater. The image mosaic below shows typical alpine or mountain glaciers developed from snow fields covering the higher elevations of parts of the Wrangell and Chugach mountains of southeast Alaska. The Bering glacier is the largest in the Chugach group, although not as broad as the Malaspina glacier off the image to the east.