In topography, prominence, also known as autonomous height, relative height or prime factor (in Europe), is a concept used in the categorization of hills and mountains. It describes how tall a peak is relative to neighbouring peaks, and in a way that makes precise the intuition that the world's second-highest mountain is K2, not a small bump near the summit of Everest.

Vertical arrows show the topographic prominence of three peaks on an island. A dotted horizontal line links each peak except the highest to its linking col.

The prominence of a summit is defined as the vertical difference between it and the highest col connecting it to a higher summit.

That higher summit is unique and is known as the parent of the summit. This gives rise to a way to put all the peaks on a landmass into a hierarchy showing which peaks are subpeaks of which others. For example, in the diagram on the right, the middle peak is a subpeak of the right peak, which is in turn a subpeak of the left peak, which is the highest point on its landmass.

The col linking a peak to its parent is called a linking col or just link.

The prominence is also the height of the summit above the lowest contour line encircling it and no higher summit (the base contour of that summit).

Prominence is interesting to mountaineers because it is an objective measurement that is strongly correlated with the subjective significance of a summit. Peaks with low prominences are really just subsidiary tops of some higher summit. Peaks with high prominences tend to be the highest points around and are likely to have extraordinary views.

See also

• Peak bagging

External links

• Mountain hierarchy terminology on Bivouac.com (http://bivouac.com/PgxPg.asp?PgxId=190)
• Topographic Prominence in Canada (http://bivouac.com/PgxPg.asp?PgxId=277)

• Edward Earl's writeup on Topographic prominence (http://www.k-online.com/~esquared/outdoor/prominence/)
• The 100 most prominent peaks in Colorado (http://www.ii.uib.no/~petter/mountains/colorado_finest.html)
• Alan Dawson's The Relative Hills of Britain (http://bubl.ac.uk/org/tacit/marilyns/)