Subsidence

Sinking of the land surface due to a number of factors, including ground water extraction.

Sinking down of part of the earth's crust due to underground excavation, such as the removal of groundwater.

Sinking or settlement of the land surface, due to any of several processes. As commonly used, the term relates to the vertical downward movement of natural surfaces although small-scale horizontal components may be present. The term does not include landslides, which have large-scale horizontal displacements, or settlements of artificial fills.

1. A descending motion of air in the atmosphere occurring over a rather broad area.

2. In hydrologic terms, sinking down of part of the earth's crust due to underground excavation, such as the removal of groundwater.

The slow sinking of air, usually associated with high-pressure areas.