A shoddy reporting system
The British Geological Survey seems unable to run a reliable survey
Campaigners opposed to fracking have made rather a lot of the fact that the British Geological Survey (BGS) says it has received more than 2,000 reports from people in Lancashire saying they felt the 2.9 magnitude tremor in the area on Bank Holiday Monday.
A number of journalists and media outlets unquestioningly repeated the figure, noting that the BGS had also revised its intensity assessment from 5 (strong) to 6 (slightly damaging) - a revision it attributed to those reports - and it has inevitably been doing the rounds on social media.
The reports referred to by the BGS are submitted via its online earthquake questionnaire. But here's the thing: BGS has no controls in place to prevent the self-reporting system from being abused, and the accounts it receives are entirely subjective.
For instance, the questionnaire (a five-part web form) asks you for your name, the address and postcode of where you experienced the tremor, along with your email address. However, BGS has no checks, automated or otherwise, to prevent people submitting wholly fictitious reports. There is literally nothing to stop ten anti-fracking activists from having submitted 200 fake reports each using made-up identities.
And, let's face it, they'd have good reason to try and manipulate the system to their advantage: in matters like this, perception can quickly become the reality, so what better than to create the perception that 2,000 Lancastrians felt this tremor when, in reality, it may only have been a tenth of that?
The questionnaire also asks people to report whether they suffered any damage to their properties, and how they reacted at the time. But talk about 'leading the witness', because instead of letting them come up with their own descriptions, lists of possible scenarios are provided that they can choose from at the click of a button - it even asks 'did anyone run outdoors in fright', practically inviting fracking opponents to ramp things up a notch.
Then there's the built-in subjectivity. Two people living in the same house can experience an earth tremor differently if, say, one is standing up on the ground floor and the other is lying down on an upper floor. The BGS clearly recognises this because it asks for those details. Anecdotally, there is evidence emerging on the Fylde that highlights this subjectivity: neighbours in the same street, for example, giving totally differing accounts, with some having felt it and others only having become aware after hearing media reports about it.
There is no doubt that some people did feel it, and it's possible that some properties may have experienced some minor cosmetic damage (something Cuadrilla, the local operator, has committed to repairing if assessed to have been caused by the tremor).
However, given the extent to which the BGS self-reporting system is open to being abused, and the subjectivity associated with using people as human 'intensity sensors', it should not be relied upon as an authentic indication of people's experience of fracking-induced seismicity, and the widely respected BGS needs to take care that it's not unwittingly being taken advantage of by the PR spinners of the anti-fracking movement.