More ridiculous reporting from the BBC: “A second tremor of 0.8 magnitude has been recorded within 24 hours at the UK's only active site for fracking.“ That is like saying that a car was driven at a speed of 1 or man was 5 tall. However, 0.8 sounds quite large doesn’t it? Or maybe quite little!

Come on BBC, does it have any scientifically educated reporters or editors?

Jit and Supertroll, thank you for your comments, I feel better informed. A couple of observations:

1. Surely it would have made sense to install the new, sensitive equipment for a reasonable period before fracking began? That way we would have known if minor tremors (sub 1) were occurring before the fracking started. At the moment, all we know is that fracking is taking place and some minor tremors that we could not detect without the new kit are now taking place (but they might have been occurring anyway). Correlation does not equal causation. Fracking and the tremors might well be linked, but without knowing with confidence what was happening (or not happening) before the fracking started we cannot be certain that the tremors now being measured by the new sensitive equipment are definitely linked to the fracking.

2. I hope that when the Government finally imposes a nuclear waste repository on Cumbria, against the expressed wishes of its inhabitants, at least as much care and concern is taken over safety issues as is the case with fracking for fossil fuels (but not apparently fracking for other energy sources).

@AK: Further.... "Tomo pray tell us when you stop using the word "earthquake" for low intensity events "

But you don't call a surfer's wave a Tidal wave - or a Tsunami (I know they are different). Terminology is graded for a reason. These Tremors are not 'earthquakes'. But an earthquake is a tremor.

@AK: "so that the risk of inducing more damaging effects..." - so what would be the seismic number for that, I wonder? Do you think that if the Swansea Barrage had gone ahead the stone quarrying would have had to abide by a similar 0.5 level before they were made to stop exploding all those charges to dislodge rock?

And, what about the 'manual fracking' that takes/took place in coal mines? There are a few homes that have been rendered uninhabitable as a result....( these points are not made in a snide way, just trying to get an expert opinion).

Second thoughts. Seismicity is not exactly an area that I can claim any great expertise. I have discussed subsurface waste disposal with a colleague tasked with evaluating its potential in a Canadian province, worked with industry geophysicists (you get to learn their language) and have discussed earthquakes with an expert within UEA. However, upon some questions here I've been giving the best of my understanding, but this could be I've been winging it. Such was the case with evaluating the energy required to shake a pile of rock compared with causing ground vibrations from a wind turbine. What I had forgotten was that most of the energy in a seismic wave is conserved as the wave is transmitted from one place to another. Thus the entire volume of rock is not being shaken at the same time. This realization came to me when I considered artificial seismic waves and the energy needed to send these waves through a rock sequence either by using explosives or a "ground- thumper". Large, but not that large.
Nevertheless, although I don't actually know how much energy might be transmitted into the ground from a wind turbine, I doubt it is anyway comparable with that needed to induce a usable seismic wave. If it did, the concrete bases wouldn't last long before being shaken to bits (I guess - winging it again).

SG. I think you may be confusing magnitude with intensity. But I have already explained why wind-induced tremors shouldn't be called earthquakes. And if you think the energy that might be imparted into the ground by the wind is in anyway comparable with the energy needed to shake a pile of rock several thousand metres thick over many square kilometres, then I despair.

GolfCharlie
"aren't these "earthquakes" exactly what was Intended by the hydraulic fracturing process?"

You have it in one. I'm sure the Industry would have hoped that the induced seismicity would have been even lower, so that the risk of inducing more damaging effects would be virtually non-existent. But that is not the case in Lancashire, no matter how much you would wish to support the fracking industry. The seismic risks are not zero. The same applies to the subsurface waste disposal industry which has been associated with damaging earthquakes. I imagine the regulations relating to avoiding seismic damage associated with subsurface waste disposal have been modified to apply to fracking in suspect areas like Lancashire.

SG
"If we put the same monitors at the base of giant wind turbines, what would they read ?
Would it be called "earthquakes" ?
No, it wouldn't. It might be called micro-tremors or vibrations, but they wouldn't have the same energy nor, more importantly, would they have the same cause - a readjustment of rock in the subsurface accompanied by over-pressures.