Question

how is an earthquake generated

Answer 1

the earthquake generated because of tactonic plates which are present in the earth crust.they are feee moving when they collide each other it generates earthquake and and when they go away it a again do that same

Answer 2

The simplest example to understand is a pressure cooker just have a look on it when the extreme hot gases are tending to come out of the close vessel.
The pressure due to heat and magma created at the core of earth when have no place to come out then it starts vibrating like a whistle of cooker.
This can create drought prone.