Collision and Subduction
Collision and subduction at convergent boundaries occurs when two tectonic plates move toward each other and the denser plate bends and slides beneath the other in a process called subduction, where it descends into the hot mantle and is recycled. In Amplify Science (California) Grade 7, Chapter 2: Understanding Plate Boundaries, students learn why subduction is a destructive plate boundary process.
Key Concepts
At a convergent boundary , two plates move toward each other and collide. If one plate is denser than the other, it cannot stay on top. Instead, it bends and slides underneath the other plate.
This downward movement is called subduction . The sinking plate descends into the hot mantle. This is a destructive process where the solid rock of the plate edge is "recycled" back into the soft, solid interior of the Earth.
Common Questions
What happens when two tectonic plates collide?
At a convergent boundary, two plates move toward each other. If one plate is denser, it bends and slides beneath the lighter plate (subduction). The denser plate descends into the hot mantle where it is recycled.
What is the difference between collision and subduction?
Collision is the general process of plates moving toward each other. Subduction specifically refers to when the denser plate bends downward and slides beneath the lighter plate into the mantle.
Why is subduction called a destructive boundary?
Subduction is destructive because the descending plate edge is melted and recycled back into the mantle. The solid rock of the plate is effectively consumed rather than being preserved.
Where is collision and subduction taught in Amplify Science Grade 7?
Collision and subduction is covered in Amplify Science (California) Grade 7, Chapter 2: Understanding Plate Boundaries.