I think that we need to be careful of the fraking debate, I think that earthquakes in the UK are a very remote threat. The UK is a very stable area of land which has not seen major earthquake or volcano activity for a very long time. So geologically it is close to dead, thus we do not need to worry ourselves too much about the earth shaking.
The reason why an earthquake occurs is that mother nature causes energy to build up in the rocks under our feet. The longer the energy has to build up the greater the potential earth quake will be. After A-bomb tests in Nevada some minor earthquakes have occurred. Maybe these bomb trials may reduce the risk of a larger earth quake by resetting the rocks in the ground.
I also think we need to be careful about the fraking question for another reason. Since the 1970s a big movement has occurred where big industry is automatically viewed as bad and small scale organic lentil weaving is automatically good. This is a load of nonsense, but a large minority of society follow this fool's errand.
The thing is that drilling for oil / gas, building cars, operating airliners, making agrochemicals (like pesticides) and nuclear activities are things which can only be done by big industry as a large capital investment is needed.
I suspect that if a small cottage collective were making MOX pellets in a shack in their back garden, making weedkiller in the garage and drilling for oil on their allotment (using fracking to increase their yield) then the small is wonderful lobby which is currently very critical of these industrial activities would be singing their praises.