Ah, just as we were starting to think that the ground below had settled down…it goes and does it again. This time press reports say that the shakes are being generated from a “patchwork of faults” below Pegasus Bay.
Wherever they’re coming from, it’s exhausting and unsettling for us here in Canterbury. And it serves to remind us of one thing, despite all the studies, we really don’t know that much about what’s happening beneath our feet.
So it just amazes me that anyone could even contemplate fracking in Canterbury when there are so many unanswered questions about the practice and its connection with earthquakes. Or “seismic activity” as the frackers prefer to call it.
We already saw, earlier this year, that fracking caused two small tremors in an area of the UK where quakes are unheard of. So the obvious question seems to be – what effects might it have in a seismically active area?
Personally, I think the answer is that nobody really knows at the moment. But let me leave you with a quote from an expert, US geophysicist Michael Hasting. Hasting works in the gas industry in the US and is in his own words someone who believes in fracking. However, here’s an extract from the Water for Gas evening that was held at Canterbury University earlier this year:
Is it possible for fracking to cause larger earthquakes?
Michael Hasting: In my opinion yes it is. If you’re injecting high pressure fluids into a fault or near a fault that’s active or near failure or stressed to a point where it’s near to go, those fluids can lubricate the fault and cause it to slip. There are many examples of this around the world.
So would it be okay for fracking to go ahead in Canterbury without first checking the earthquake safety of the region?
No, you shouldn’t do it. It would be absolutely irresponsible to go out in an area like Canterbury which is a known area of tectonic fractures and start injecting fluids without understanding the reservoir, the system and where you’re injecting these fluids. So you want to determine where these faults are and how close they are to failure before anything else is done
You can’t 100% guarantee that you won’t induce a large scale event in a tectonically active area like New Zealand.