Jut (topography)

Calculating topographic jut

In topography, jut is a measure of the base-to-peak rise and visual impressiveness of a mountain summit or other landform. It describes how sharply or impressively a location rises above surrounding terrain by factoring both height above surroundings and steepness of ascent.

Description

A mountain with a jut of X can be interpreted to rise as sharply or impressively as a vertical cliff of X. For example, a vertical cliff of height 100 meters, a 45° slope of height 141 meters, and a 30° slope of height 200 meters all measure a jut of 100 meters and can be interpreted to rise equally sharply. Jut can be further decomposed into base-to-peak height and base-to-peak steepness, where jut equals base-to-peak height multiplied by the sine of base-to-peak steepness.

Definition

Jut $J=\max {H'}$ is the maximum angle-reduced height (symbol H'), which can be defined as the vector projection, in the line of sight, of the peak's height (or vertical separation), H:

$H'=H|\sin {e}|$

where e is the summit's elevation angle. Height, angle-reduced height, and jut have unit of length (meter or feet). While height and angle-reduced height depend on the viewing location around the peak, jut is a constant value for a given peak. Base is the location where angle-reduced height is maximized.