Question

Describe the mechanism of occurrence of an earthquake with the help of pictorial representation.

Answer 1

Hint: The inner surface of Earth is considered to be divided into a number of plates. These plates move freely under the surface. These plates in their motion also interact, these interactions lead to various natural phenomena such as volcanic islands, mountains, earthquakes and many others.

Complete solution: Earthquake is the shaking or trembling of the earth surface which causes energy to release suddenly. An earthquake different ranges from faint tremor to a wild motion capable of shaking buildings apart. Minor tremors are caused by gentle waves of vibration within the earth’s crust, they occur every few minutes. Major earthquakes are usually caused by movement along faults, and can be very disastrous.

The main reason for the occurrence of earthquakes is because of interactions between oceanic crust and continental crust.

Movement of tectonic plates are responsible for earthquakes, mechanism of tectonic earthquake,
1. Earthquakes occur when the continental crust of the Earth collides with another continental plate.
2. When continental plate collides with another continental plate, there is no magna formation; instead the plates collide and break into pieces.
3. During this collision, energy is released. This energy is released in the upward direction.
4. There is sometimes formation of mountains as shown in the above figure.
5. Earthquakes also occur when two plates pass by each other without colliding but slipping off. These collisions lead to the formation of the San Andreas fault in California, USA.
6. Powerful earthquakes are responsible for the formation of Himalayas, India.

Note: Earthquake is measured on a magnitude scale known as Richter scale. The magnitude is in the range of $0 - 10.$ Another scale to measure intensity of earthquake is Mercalli scale having range, $1 - 12$. Remember that movement of tectonic plates lead to many other disasters too other than earthquakes.