Surface map

In mathematics, geology, and cartography, a surface map is a 2D perspective representation of a 3-dimensional surface.^[1] Surface maps usually represent real-world entities such as landforms or the surfaces of objects. They can, however, serve as an abstraction where the third, or even all of the dimensions correspond to non-spatial data. In this capacity they act more as graphs than maps.^[2]

A 3D surface map of Mt. St. Helens with a 2D contour map above for comparison.