Earthquake prediction is very unreliable, however there are several established methods that have been used to correctly predict earthquakes in the past.Satellite GPS or on ground laser measuring: Used to measure and observe any ground movements that could indicate plate movement prior to an earthquake. Seismometer: Measures tiny vibrations within the ground caused by plate movement, an increase in these vibrations can precede an earthquake. Radon gas: Microfractures form within the ground prior to an earthquake, these fractures allow radon gas to escape from the ground. This means that an increase in radon gas indicates an imminent earthquake. Animal behaviour: Unusual animal behaviour has been observed prior to earthquakes in the past. This is likely due to some animals being highly sensitive to vibrations that can occur with ground movement before an earthquake. Seismic gap theory: Theory that earthquakes can be predicted by observing the time gap between past earthquakes in an area. The average time between past earthquakes, and the time since the last earthquake can then be used together to roughly predict an earthquake.