GEOLOGY

Detailed explanation-1: -The process by which ocean floor sinks beneath a deep-ocean trench and back into the mantle is called subduction (sub duk shun). As subduction occurs, crust closer to a mid-ocean ridge moves away from the ridge and toward a deep-ocean trench. Sea-floor spreading and subduction work together.

Detailed explanation-2: -Subduction is the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle.

Detailed explanation-3: -Trenches are formed by subduction, a geophysical process in which two or more of Earth’s tectonic plates converge and the older, denser plate is pushed beneath the lighter plate and deep into the mantle, causing the seafloor and outermost crust (the lithosphere) to bend and form a steep, V-shaped depression.

Detailed explanation-4: -Subduction happens where tectonic plates crash into each other instead of spreading apart. At subduction zones, the edge of the denser plate subducts, or slides, beneath the less-dense one. The denser lithospheric material then melts back into the Earth’s mantle.

Detailed explanation-5: -In the ocean, tectonic processes continuously create and destroy oceanic crust. New crust is created at mid-ocean ridges and moves away from them over millions of years. Old crust is destroyed when it reaches seafloor trenches.