subsidence

n. gradual sinking of land caused by natural shifts or human activity; (Medicine) remittal, remission, decrease in the manifestations (of a disease); sinking in bone;

In geology, engineering, and surveying, subsidence is the motion of a surface (usually, the Earth's surface) as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation. There are several types of subsidence, listed below in order of increasing scale: Dissolution of limestone Subsidence frequently occurs in karst terrains, where dissolution of limestone by fluid flow in the subsurface causes the creation of voids (i.e. caves). If the roof of these voids becomes too weak, it can collapse and the overlying rock and earth will fall into the space, causing subsidence at the surface. This type of subsidence can result in sinkholes which can be many hundreds of meters deep and can provide areas of ecological isolation which see the evolution of new branches of animal and plant life.
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Noun
1. an abatement in intensity or degree (as in the manifestations of a disease); "his cancer is in remission"
(synonym) remission, remittal
(hypernym) suspension, respite, reprieve, hiatus, abatement
(hyponym) resolution
(derivation) subside, lessen
2. a gradual sinking to a lower level
(synonym) settling, subsiding
(hypernym) sinking
(derivation) subside
3. the sudden collapse of something into a hollow beneath it
(synonym) cave in
(hypernym) collapse
(derivation) subside

n. subsidence

(n.)
Alt. of Subsidency