Feeds

Shale gas operations triggered Blackpool tremors

Deep-level drilling caused two minor earthquakes

Remote control for virtualized desktops

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. ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
I'll be back (and forward): Hollywood's time travel tribulations
Quick, call the Time Cops to sort out this paradox!
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
NASA launches new climate model at SC14
75 days of supercomputing later ...
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
prev story

Whitepapers

Seattle children’s accelerates Citrix login times by 500% with cross-tier insight
Seattle Children’s is a leading research hospital with a large and growing Citrix XenDesktop deployment. See how they used ExtraHop to accelerate launch times.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.