Earthquakes cannot currently be systematically predicted. However, phenomena that could herald earthquakes are being monitored, including earthquake lights, earthquake clouds, elevated concentrations of radon, seismic quiet, electromagnetic signals, conspicuous animal behaviour and foreshocks, which sometimes precede main quakes (though only after a main quake does it become clear that they were actually foreshocks). But so far no patterns have been observed that could enable us to predict earthquakes reliably.
Nonetheless, three factors are known to have close links with earthquake prediction:
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