When does an elastic rebound happen?

Answer 1

The sudden return of an elastically-deformed rock to its original shape when a load is removed or a stress released. This often occurs in earthquakes, as rocks either side of a slip fault, which have been stressed by friction along the fault plane, overcome static friction and rapidly rebound.

Elastic rebound must not be confused with isostatic rebound, which is a much slower process in which mantle material flows under pressure into areas under the crust where large loads such as oceans or ice sheets have been removed, thus forcing the crust to rise where the load has been removed and fall elsewhere. Because of the large scales involved and extremely high viscosity of the mantle material, isostatic rebound very slow. The ground surface in the area of Scandinavia is still rebounding at a measurable rate (about 10mm per year) as a result of the melting of the Weichsel ice sheet ten thousand years ago.

Answer 2

Elastic Rebound is the sudden return of elastically deformed rock to its underformed shape

Answer 3

when a boundary between two plate has built up energy from the past years and as some might say, needs to let it rip, basically it finally releases its energy resulting in a earthquake

Answer 4

When a body collides with another body and is not completely deformed, transmiting all its energy to the other body.

Bounce.