A common question seismologists are asked is: Can earthquakes be predicted?

Thanks to numerous seismometers installed all over the earth’s surface, seismologists are now getting a better understanding of earthquakes and their occurrence. By observing the movement of tectonic plates and by looking at the earthquake history of a particular region, seismologists can estimate when a major quake is likely to occur in that particular area.

However, this is all based on mathematical probability and cannot be used to predict the exact time when an earthquake will occur. A classical example is the case of Parkfield, California, where moderate-sized earthquakes of around magnitude six were observed to occur approximately every 22 years. After an earthquake occurred there in 1966, scientists were pretty sure that the next similar earthquake would occur close to 1988. But it actually happened in 2004 – 16 years after the prediction.

An ‘earthquake cycle’ is not a reliable tool for earthquake prediction. Nonetheless, probabilistic estimates are an important tool for preparing a country’s infrastructure for earthquake resilience.

Quake prediction should not be confused with earthquake early warning, which refers to the technology used to alert people when seismic waves are approaching a particular location, after a quake has occurred some distance away.