subduction

American  

[suhb-duhk-shuhn] / səbˈdʌk ʃən /

noun

1. an act or instance of subducting; subtraction or withdrawal.

2. 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.

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subduction British  

/ səbˈdʌkʃən /

noun

1. the act of subducting, esp of turning the eye downwards

2. 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

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subduction Scientific  

/ səb-dŭk′shən /

1. 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.

2. Compare obduction

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Etymology

Origin of subduction

1570–80; < Latin subductiōn-, stem of subductiō pulling up, computation; see subduct, -ion

Explanation

In geology, subduction is what happens when one tectonic plate moves underneath another. Most strong earthquakes are caused by subduction. Subduction causes the most powerful earthquakes, and over time it's also what creates volcanoes and mountains. When you study geology or earth science, you'll learn about areas of the earth called "subduction zones," regions where subduction is occurring and earthquakes are relatively common. Before 1970, the word was used to mean "removal of noxious substances from the body."

Example Sentences

While collecting sediment cores from the Cascadia subduction zone off Oregon and northern California, the team accidentally drifted off course.

From Science Daily • May 2, 2026

Over millions of years, this gradual loss of momentum can bring the entire subduction system to a stop.

From Science Daily • Apr. 29, 2026

If subduction zones continued indefinitely, continents would keep piling up, oceans would disappear, and much of Earth's geological history would be erased.

From Science Daily • Apr. 29, 2026

For years, researchers suspected these fragments were linked to dying subduction zones, but the exact process was unclear.

From Science Daily • Apr. 29, 2026

Just off its east coast, deep beneath the seafloor, giant chunks of Earth’s lithosphere and crust are being sucked beneath the country in a process called subduction.

From "Meltdown" by Deirdre Langeland