Unit-vector density mapping

An automated mapping technique, termed unit-vector density mapping, is introduced as a new method of displaying continuous surface vector quantities. With this graphic procedure, the density of short standard-length line segments (unit-vectors) with, or without, arrowheads represents geographical magnitudes and unit-vector orientation shows direction or movement. This paper describes the plotting algorithms for producing unit-vector density maps and demons-trates the versatility of this technique in a number of geoscientific applications.