As regards 'fracking' (horrible cheap'n'cheerful American/Australian tag), have we not been here before, all through the centuries? Coal, salt, gas, oil, even (in South Africa) ground de-watering to facilitate diamond mining - wherever a volume of material, and hence mechanical support, is removed from the Earth's crust and nothing put back to replace it, there is bound to be subsequent compaction/collapse, often at considerable distance and time from the event. This technique, if unwisely applied in the West Somerset oilshale area (I assume this is the connection in the post of 3rd November), would undoubtedly affect the hydrology of the Lias basin where it abuts the fault planes of the Palaeozoic massifs and cause movement long term - not a great idea in the vicinity of Hinkley Point! The rocks here are heavily fractured and folded already.
To illustrate the point, the photo above shows an unsuspected flexure recently discovered in the Charmouth Mudstone at Bishops Cleeve. This is due to valley bulging at the foot of the Cotswold scarp and just poised to go walkabout. I think the human race really is going to have to start being very careful at this stage.
Victorian minemasters were very adept at simply ignoring the environmental consequences of their actions - vide the 1000 acre sulphuric acid swamp on Parys Mountain due to the uncontrolled tipping of copper mining waste nearly 200 years ago, and the terraces of cottages which still lie buried under the colliery batch at Dunkerton.
3 comments:
Fracking is American technology so it seems reasonable for them to utilise their own term to describe it.
There is no removal of material apart from the subsequent flow of oil and gas from the rock. The rock is split by hydraulic pressure and the created fracture filled with a proppant (usually sand or ceramic beads) to create a flow path.
There is no record of compaction or collapse associated with fracking. There is massive information from the USA where this technology is widely used that the created fractures are very localised. I do not see why the flexure you describe has any relation to hydraulic fracturing?
I do agree with you that the human race should be very careful about our environment, that is why Oil and Gas activities are regulated by State Mines and Environmental Agencies. You should also recognise that the employees of Oil Companies who manage the activities are trained Geologists Geophysicists and Engineers who are interested in preserving the environment. The example of Victorian minemasters is relevant only because it reminds us how badly things were done 150 years or so ago.
if you want to have gas and electricity delivered to your home and petrol available for your car and fertiliser available to provide food at the local supermarket - there has to be an oil and gas industry.
Ill informed comments like this blog do not help a rationale discussion.
@RH
I presume you haven't read the preceding post, and the linky therein. This covers the bulk of your contribution.
I believe that edie is concerned about the sort of 'unknown unknowns' that might result. By this I mean events like the Ekofisk subsidence and the Abbeystead explosion, the second, deadly, the first merely horrendously expensive.
Regards
Bruce
I have to clarify and to apologise about one aspect of my reply above. The article was not by edie but by another person who wished to remain anonymous.
Regards
Bruce
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