1. n. [Geology]

A worldwide grid system of rectangular map coordinates that uses metric (SI) units.

A location is specified on the basis of its location within one of 60 zones worldwide of 6° of longitude and 8° of latitude each that are subdivided into subzones that are 100,000 m [330,000 ft] on each side. Locations consist of a series of numbers and letters that can be accurate to within an area of one square meter. The headquarters of the Geological Society of America are at 13TDQ8743172 (Merrill, 1986).

Information about the UTM grid, including grid ticks on quadrangle maps, can be found on most maps produced by the US Geological Survey. Latitude and longitude coordinates, or geographic coordinates, are another means of locating a point at the Earth's surface, but the accuracy, computer compatibility, and uniqueness of UTM have resulted in its finding acceptance within the scientific community.

See related terms: base map