What is elastic rebound in subduction zones?
Oblique view of a highly generalized animation of a subduction zone where an oceanic plate is subducting beneath a continental plate. (See sketch below for parts.) This scenario can happen repeatedly on a 100-500 year cycle. The process which produces a mega-thrust earthquake would generate a tsunami, not depicted here.
Keypoints:
During subduction:
- the heavier, thinner plate dives beneath the more-buoyant plate
- Two tectonic plates are locked at the contact by immense friction.
- The overlying plate is forced backward creating strain
- When friction is overcome the plate rebounds along the contact to a more-relaxed position