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.

---

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

---

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

---

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

See Examples For:

subduction

Island arcs, chains of volcanoes that develop above subduction zones where one oceanic plate descends beneath another, are often unusually rich in gold.

From Science Daily ● Jul. 29, 2026

Although it sits near a subduction zone, the chemical makeup of its lava more closely resembles volcanoes formed above hotspots, even though no hotspot exists beneath the region.

From Science Daily ● Jul. 10, 2026

"Spreading centers are associated with less explosive activity, while the most explosive eruptions are usually along subduction zones and involve large stratovolcanoes."

From Science Daily ● Jul. 10, 2026

These strike-slip earthquakes can occur at shallower depths than subduction quakes, where one tectonic plate is forced below another.

From The Wall Street Journal ● Jun. 25, 2026

There, the Pacific Plate slides beneath the North American Plate in what’s known as a subduction fault.

From "Meltdown" by Deirdre Langeland