INDIAN GEOGRAPHY

Detailed explanation-1: -In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.

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: -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.