To Hell and Frack: UK Shale Gas Reserves

[PsychoSerenity]

I wonder if fracking prevents earthquakes by bleeding stress energy away through minor shakes.

Well I'm no geologist, but I wouldn't have thought so. The fact that the (relatively) minor stress caused by fracking is enough to break the rocks and cause the minor shakes, suggests to me that if there were a natural tectonic build up of stress, it would also get released through minor shakes.

In fact, breaking minor faults ahead of their time, as it were, might reduce the terrain's ability to release stress through minor shakes in the (probably quite distant) future.

[rainbow]

I would tend to agree that the forces involved in fracking are very minor compared to natural seismic events.

[PsychoSerenity]

I would tend to agree that the forces involved in fracking are very minor compared to natural seismic events.

Well not compared to natural seismic events in a place with a very low level natural seismic events. And it's still probably not a good idea to be causing them near cities of old masonry buildings not designed to cope with them.

[mistermack]

I disagree.
When stress builds up, it is always going to cause shaking when it's released. Fracking will not CAUSE a quake.
It might bring it forward, that's all. A quake that had to happen anyway.
And yes, it would definitely reduce the severity. If a quake happens early, the size must be less.

If one big quake was substituted by two smaller ones, there is BOUND to be less damage.
Take it to the extreme, a thousand small quakes instead of one big one. The damage would be insignificant.

[PsychoSerenity]

I disagree.
When stress builds up, it is always going to cause shaking when it's released. Fracking will not CAUSE a quake.
It might bring it forward, that's all. A quake that had to happen anyway.
And yes, it would definitely reduce the severity. If a quake happens early, the size must be less.

If one big quake was substituted by two smaller ones, there is BOUND to be less damage.
Take it to the extreme, a thousand small quakes instead of one big one. The damage would be insignificant.

Not necessarily. Given enough time, pressure or heat, rocks can deform plastically. If the stress build up is slow enough e.g. in areas with little tectonic activity, the stress can simply dissipate as the rocks slowly bend into a new shape. Fracking could cause quakes that would otherwise never happen.

[rainbow]

I disagree.
When stress builds up, it is always going to cause shaking when it's released. Fracking will not CAUSE a quake.
It might bring it forward, that's all. A quake that had to happen anyway.
And yes, it would definitely reduce the severity. If a quake happens early, the size must be less.

If one big quake was substituted by two smaller ones, there is BOUND to be less damage.
Take it to the extreme, a thousand small quakes instead of one big one. The damage would be insignificant.

Not necessarily. Given enough time, pressure or heat, rocks can deform plastically. If the stress build up is slow enough e.g. in areas with little tectonic activity, the stress can simply dissipate as the rocks slowly bend into a new shape. Fracking could cause quakes that would otherwise never happen.

That doesn't make sense. Fracking, if it has any effect, must result in an increased plasticity, not less.

[PsychoSerenity]

I disagree.
When stress builds up, it is always going to cause shaking when it's released. Fracking will not CAUSE a quake.
It might bring it forward, that's all. A quake that had to happen anyway.
And yes, it would definitely reduce the severity. If a quake happens early, the size must be less.

If one big quake was substituted by two smaller ones, there is BOUND to be less damage.
Take it to the extreme, a thousand small quakes instead of one big one. The damage would be insignificant.

Not necessarily. Given enough time, pressure or heat, rocks can deform plastically. If the stress build up is slow enough e.g. in areas with little tectonic activity, the stress can simply dissipate as the rocks slowly bend into a new shape. Fracking could cause quakes that would otherwise never happen.

That doesn't make sense. Fracking, if it has any effect, must result in an increased plasticity, not less.

Why must it? I wouldn't be surprised if it could in some cases, but I see no particular reason why it couldn't also decrease it in others. Altering different pressures and stresses in different layers of rock, - I'd have thought the effects on local geology from one case to the next would be rather unpredictable. Happy to hear some evidence that proves me wrong. I must admit I have little knowledge of the extent of modern geological surveys or the ability of the models to accurately predict the effects. But there have been plenty of suggestions that fracking has caused earthquakes, - were these predicted or predictable? Could fracking be restricted to areas where it would only have a positive effect on the geology?

[rainbow]

I think the evidence shows that tremors were 'induced', rather than 'caused' by fracking. The implication is that the stresses pre-existed, and that fracking resulted in these being released.
Whether this would have happened naturally at a later stage is not known.

[mistermack]

Not necessarily. Given enough time, pressure or heat, rocks can deform plastically. If the stress build up is slow enough e.g. in areas with little tectonic activity, the stress can simply dissipate as the rocks slowly bend into a new shape. Fracking could cause quakes that would otherwise never happen.

You can make a theoretical case for that, but, without doing days of research, I would bet that that would only apply at much greater depths than frackable depths. It's generally occurring at enormous temperatures and pressures, which usually exist at extreme depth.
Maybe in volcanic regions you might get it nearer the surface, but they are unlikely to be fracking there anyway.
I would say that it's highly likely that if the stress is such that some fracking could set off a quake, then it would have fractured anyway. The forces of fracking are insignificant, compared to the forces of nature.

For a tiny event to trigger a huge event, the huge event needs to be right on the brink.
Take the case of a pebble causing an avalanche.
One pebble can start an avalanche, that's true. But if the pebble doesn't move, which is more likely? A slow and gradual landslip over years, or some other pebble triggering the avalanche?

I would say it's thousands to one that the avalanche would happen anyway.

[Seth]

EPA study finds no leakage of fracking compounds into water supply in PA.

Jul 25, 2012
EPA declares water in Pa. 'fracking' village safe to drink

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By Michael Winter, USA TODAY
Updated 2012-07-25 8:02 PM

CAPTION
By Matt Rourke, AP
The U.S. Environmental Protection Agency today announced it had ended testing of drinking water in a northeastern Pennsylvania community and declared it safe to drink, despite residents' complaints of pollution from natural gas drilling.

The EPA began testing four wells in Dimock late last year after some residents complained of illnesses involving their nerves, stomachs and skin. They blamed Houston-based Cabot Oil & Gas Corp. for contaminating their water with chemicals used in hydraulic fracturing, or fracking.

The Oscar-nominated 2010 documentary Gasland featured Dimock residents lighting tap water on fire. Geologists say such methane contamination can occur naturally in well water. The area, in Susquehanna County, sits atop a section of the Marcellus Shale formation, which spans several Mid-Atlantic states.

Between January and June, the EPA tested and re-tested private wells serving 64 homes. In May, the agency issued preliminary results that showed no signs of contamination from fracking.

BLOG: EPA: Pa. village's water not polluted by gas fracking

"The sampling and an evaluation of the particular circumstances at each home did not indicate levels of contaminants that would give EPA reason to take further action," Regional Administrator Shawn Garvin said today in a news release. "Throughout EPA's work in Dimock, the Agency has used the best available scientific data to provide clarity to Dimock residents and address their concerns about the safety of their drinking water."

In declaring the water safe, the agency also said it would stop providing water to four homes.

One resident rejected the agency's all-clear.

"I don't care what EPA says. The water is still polluted," Ray Kemble told the Associated Press. "Do something about it."

Cabot's president and CEO welcomed the findings.

"The conclusions reached by the EPA mirror those previously made by the Pennsylvania Department of Environmental Protection and Cabot," Dan Dinges said in a statement. "I am satisfied that concerns over water quality have been studied to the highest levels of scrutiny."

The EPA has posted key documents pertaining to oil and gas development in the Mid-Atlantic region.

[pErvinalia]

Gaslands2 is available to watch online. I'm just watching it now.

http://thoughtmaybe.com/gasland2/?lang=en

[rainbow]

"I don't care what EPA says. The water is still polluted," Ray Kemble told the Associated Press. "Do something about it."

Never mind the facts.

[pErvinalia]

Why are you so keen to believe that fracking is safe? There's been so much anecdotal evidence (as well as mounting scientific evidence) to suggest that it is potentially not. If you don't work in the industry, I suspect you have a close friend or family member who does. You seem to show very little sceptical ability in regards to this topic.

[cronus]

Safety isn't the issue....my gas bill is the issue and to me what happens to locals in the vicinity of fracking is their own double edged sword. If they don't want money they don't have to frack. Choices, choices and choices.

[Tyrannical]

The fracking industry is in almost total denial that fracking can "cause" tremors, which is a shame because I think the possibility that fracking releases tectonic energy in a "safe" way is really worth studying. We could have discovered a way to prevent earthquakes!