It is very difficult to predict an earthquake, however, two methods are used for this - (i) the measurement of various types of physical changes occurring immediately before the earthquake and (ii) the historical background of the earthquake ie long-term earthquake of the affected area History.
The physical changes that occur during an earthquake are as follows:
1. "P" wave velocity: Many small earthquakes make changes in the velocity of "P" waves that become normal before a large earthquake. These changes are measured by an earthquake.
2. Land uplift: Before sliding down the plot before the earthquake, numerous small cracks fall into the rocks of a large area. In these newly formed cracks, the underground water enters. The presence of water works like a hydraulic jack, which creates a ridge in the rocks. So, before the big earthquake, the land blooms in the dome shape or gets up. This change is called Dilatancy.
3. Radon Emission: The exhaust of Raidon gas exceeds a large earthquake. Therefore, monitoring the evacuation of Ryan gas can give warning of any major earthquake coming.
4. Animal behavior: It is often seen that before the arrival of a major earthquake, organisms, especially those living in bills, behave in an extraordinary manner. Ants, termites and other living organisms come out of their hiding places. The birds are loud-tongued and the dogs bark and weep in a different way.