Snake coils is a descriptive term used by physical geologists and glaciologists to describe the "snake coil"-like shape that occurs along certain ablation lines. Essentially miniature tunnel valleys, the peculiar natural shapes were first described by French geologist Jean-Jerome Peytavi in 1973 during an expedition to northern Greenland, and later confirmed by a team of Danish geologists. It is believed that snake coils are formed through the same mechanism as tunnel valleys.