Scientists have observed that certain phenomena seem to occur before an earthquake as the pressure within the plates intensifies. Myriads of tiny cracks appear in the rock, causing it to expand and uplift the ground above it. The pressure squeezes water out of the rock, thereby 14 nearby water levels. Also the rock becomes more resistant to electric current, and radon gas is released. Scientists hope that these 15 phenomena will provide keys to predict when and where an earthquake will occur.