How can radon gas be used by seismologists

Radon diffuses out of the earth in small, variable quantities all the time, but this can increase when reductions in pressure allows radon or fluids carrying I. Solution to escape to the surface, such pressure drops can accompany or precede the sharing of rocks in an earthquake!

I guess that the use of radon is that it will help diffuse out the Earth but it can increase the reductions in pressure which is helpful in an earthquake. The solution will escape to the surface as its pressure will drop to stop an minimize the magnitude of an earthquake.