Where does relief collide?

The difference in elevation across a stretch of land: local relief is the vertical distance between the highest and lowest ground within a given area, and it is a basic measure of how rugged or subdued a landscape is. Montgomery and Brandon's 2002 Topographic controls on erosion rates in tectonically active mountain ranges treated mean local relief as a property of terrain that scales with erosion rate once hillslopes approach a threshold steepness. The referent is a geometric property of the land surface, measured in metres of elevation range over a chosen area, not a form raised from a background, a remedy granted by a court, or a feeling of release.[1]

Unit

A landscape's elevation range, in metres over a given area

Recovery means

Left without uplift, erosion wears high ground down and fills low ground, so relief decays as a landscape is worn toward a subdued surface

Measured by

Computed from a digital elevation model as the range of elevation within a moving window, or read from contour spacing on a topographic map

A sculptural form that projects from a background surface to which it stays attached, so it is seen from the front rather than fully in the round: the degree of projection runs from shallow bas-relief to bold high relief, and the raised form reads through the real shadow it casts. Rogers's 1974 Relief Sculpture set out how a relief works as a distinct art form, part carving and part picture, governed by the depth of its projection and the light it catches. The referent is a worked surface in stone, metal, or clay, described by how far it stands out from its ground, not an elevation range in a landscape, a court's remedy, or an emotion.[2]

Unit

A form's projection from its background, from shallow to bold

Recovery means

Not applicable

Measured by

Judged by the depth of projection relative to the background plane and by how the raised form catches and casts light

The pleasant emotion felt when a feared or threatening outcome fails to occur or comes to an end: relief marks the passing of something bad rather than the arrival of something good, and it can follow a near miss or the close of an ordeal. Sweeny and Vohs's 2012 On near misses and completed tasks distinguished the relief of a threat averted, which prompts counterfactual reflection on what almost happened, from the relief of a demand ended, which brings a quieter settling. The referent is a felt emotional state that follows the removal of a threat, reported and rated by the person who feels it, not a landscape's elevation, a raised form, or a court's remedy.[3]

Unit

A felt easing after a threat passes, by its reported intensity

Recovery means

The state subsides as the averted threat recedes from mind and arousal returns toward baseline

Measured by

Assessed by self-report ratings of felt relief and by physiological and behavioural signs of easing once the threat has passed