How an earthquake is generated?
If you throw some pieces of paper in a boiling water in a pane – what will happen ? The pieces of paper will move around in a random style colliding with each other and moving one under the other!This is because convectional heat energy is releasing and hence moving these pieces.
The same way earthquakes are release of internal energy of earth. Tectonic plates are floating on the molten material as crustal structures. When these plates collide with each other or one plate under the other breaks apart on reaching the elastic limit then an earthquake occurs.
How earthquakes are measured?
Earthquakes are measured on rector sacle – a mathematical formula