- an act or instance of subducting; subtraction or withdrawal.
- Geology. the process by which collision of the earth's crustal plates results in one plate's being drawn down or overridden by another, localized along the juncture (subduction zone) of two plates.
Origin of subduction
- geology a long narrow, often arcuate, zone along which subduction takes place
- the act of subducting, esp of turning the eye downwards
- geology the process of one tectonic plate sliding under another, resulting in tensions and faulting in the earth's crust, with earthquakes and volcanic eruptions
early 15c., "withdrawal, removal" (originally of noxious substances from the body), from Latin subductionem (nominative subductio), noun of action from past participle stem of subducere (see subduce). Geological sense is attested from 1970, from French (1951).
- A convergent plate boundary where one plate subducts beneath the other, usually because it is denser. The western coast of South America is roughly coincident with a subduction zone in which a plate consisting of ocean floor is subducting beneath the continental mass of South America.
- A geologic process in which one edge of one lithospheric plate is forced below the edge of another. The denser of the two plates sinks beneath the other. As it descends, the plate often generates seismic and volcanic activity (from melting and upward migration of magma) in the overriding plate. Compare obduction.