Question

Crustal instability is the major factor responsible for earthquakes. Give reasons

Answer 1

All the earthquakes are caused due to excessive pressure on the earth's crust.  Due to tremendous pressure, earth's surface breaks and stretches outward in all the directions.  Volcanic gases below the earth's crust can cause instability on the surface.  Sudden movements of rocks can disturb the crust causing earthquakes.  Mining activities, constructing dams, landslides and blasting of rocks can disturb earth's crust causing earthquakes.

Answer 2

Rocks are made of elastic material and s o elastic strain energy is stored in them during the deformations that occur due to the gigantic tectonic plate action that occur in the earth.