To predict earthquakes, geologists look for a combination of the following signs:

To predict earthquakes, geologists look for a combination of the following signs: increases in well water levels, decreases in radon gas in groundwater and foreshocks. The most obvious and direct sign of an earthquake is foreshock that is an earthquake which usually takes place before a larger seismic activity. It is also called an aftershock due to the fact that it is a mini-quake that you can only see before a real earthquake.