Feeds

Shale gas operations triggered Blackpool tremors

Deep-level drilling caused two minor earthquakes

Build a business case: developing custom apps

Shale consortium Cuadrilla says deep-level drilling caused two minor earthquakes in Lancashire, but they were so small hardly anyone felt them. The group's report, a Geomechanical Study of Bowland Shale Seismicity, which coughed to the tiny tremors, was published on Wednesday.

Cuadrilla says a quake of magnitude 2.3 on 1 April, and one of 1.5 on 27 May, were probably caused by fracking - or hydraulic fracturing. The group said:

In the Lancashire area of the UK, there have been many mining-induced seismic events at comparatively shallow depths of around one kilometre below the surface, that measured up to 3 on the Richter scale. The Preese Hall-1 well is more than 1.5 kilometres below the earth’s surface so events of similar strength are very unlikely to cause any damage at the surface.

Fracking takes place for a short but intense period, after which the heavy machinery departs and the "pad", or well head, collects the gas released.

Neither the quakes, nor their intensity, come as much of a surprise. Coal excavation causes hundreds of minor earthquakes around the globe every year - but shale 'fracking' typically takes place at a much deeper level: several thousand metres below most quake-inducing coal seams. The Lancashire shale bed lies 7,000 to 12,000 feet below the surface.

Cuadrilla attributes the seismic activity to the repeated injection of the fracking fluid - water with a trace of lubricant - into a pre-existing critically stressed fault, but says this is unlikely to reoccur. Still, Cuadrilla suspended drilling as a precaution.

All the same, the group accepts the conservative German standard for safe ground vibration, which sets the maximum magnitude at 2.6 and recommends mitigation measures if seismic activity exceeds magnitude 1.7 - after which the group should stop water injection and reduce pressure.

A more detailed explanation can be found here. ®

Securing Web Applications Made Simple and Scalable

More from The Register

next story
World Solar Challenge contender claims new speed record
One charge sees Sunswift travel 500kms at over 100 km/h
SMELL YOU LATER, LOSERS – Dumbo tells rats, dogs... humans
Junk in the trunk? That's what people have
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
Jurassic squawk: Dinos were Earth's early FEATHERED friends
Boffins research: Ancient dinos may all have had 'potential' fluff
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.