When Do Subduction Occur?

Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth's interior. Not all convergence leads to subduction. Continental rocks are too buoyant to be forced downward, so when continents collide, they crumple but stay at the surface.

When subduction occurs what is formed?

The area where subduction occurs is known as the subduction zone. When one plate begins to slip underneath another one a trench is formed. The earthquakes that result due to the plates grinding against each other often cause magma to spill out through the trench in submarine volcanoes.

Where does subduction occur?

Subduction zones occur all around the edge of the Pacific Ocean, offshore of Washington, Canada, Alaska, Russia, Japan and Indonesia. Called the "Ring of Fire," these subduction zones are responsible for the world's biggest earthquakes, the most terrible tsunamis and some of the worst volcanic eruptions.