Bishop Hill Manmade earthquakes
Jun 1, 2011 Energy Commenters on unthreaded have been pointing to a story this morning about fracking operations near Liverpool Blackpool being halted because of a possible link to earth tremors.
A brief Googling suggests that this is possible, but the implications are not exactly scary.
Earthquakes induced by human activity have been documented in a few locations in the United States, Japan, and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil, and the filling of large reservoirs for water supplies. Most of these earthquakes were minor. Deep mining can cause small to moderate quakes and nuclear testing has caused small earthquakes in the immediate area surrounding the test site, but other human activities have not been shown to trigger subsequent earthquakes. Earthquakes are part of a global tectonic process that generally occurs well beyond the influence or control of humans. The focus (point of origin) of an earthquake is typically tens to hundreds of miles underground, and the scale and force necessary to produce earthquakes are well beyond our daily lives.
Reader Comments (28)
One has to wonder what the implications are for the proposed sequestration of CO2 by pumping it, at great pressure, into the ground.
Presumably, any CO2-induced mini-quakes will be rapidly and heavily glossed over.
They will be classed as Good Earthquakes by the EU, simples.
Not sure about CO2. As I understand it, the oil and gas industry would be quite happy for cheap, bulk CO2 for enhanced recovery, especially if they're being paid to sequester it. Whether it would cause quakes would presumably depend on the pressure used, which would depend on the geology. Bigger risk seems to be risk of large leaks and Lake Nyos type loss of life.
Earthquakes are more commonly seen after injecting fluid for geothermal heat extraction (see for example Switzerland . It is possible to get earthquakes up to a level of about 5 with deep mining in South Africa, or in the potash deposits in Germany. But an earthquake of around 1.4 as this is reported to be is very minor.
Even the great Wikipedia has sections on microquakes:
http://en.wikipedia.org/wiki/Microearthquake
http://en.wikipedia.org/wiki/Earthquake_Game ;-)
Microquakes can be expected around geothermal energy projects and CCS facilities as a result of their operations. Strange there should be no mention of these ... or maybe it isn't.
A few major service companies offer a tool to monitor the fracking of a well in real time. The concept is that you would be wasting your fracking fluid (and money spent on that material) if it's fracked into a zone that is not your target zone. Baker Hughes is one company I know about. They require a nearby well so the resolution of the seismic energy can be closely monitored. If the frac job overpowers the target interval, the seismic monitoring can detect this, and the crews doing the fracking can change the parameters in time to prevent fracking outside of the zone. Normally the parameters include pressure and volume which can be changed in a live environment. Often these larger fracs are "multi-stage" which means they are done section by section of the (mostly) horizontal well.
Point is, if the fracking process causes additional stresses in the nearby rocks, that's not impossible to see.
Likewise, it would be hard to model an earthquake taking place some time after a frac job that could be caused by the fracked rocks. (By "some time" I mean after the initial frac fluid has been recovered. )
That said, it is always possible for fluid in rocks to cause some earthquakes. The movement of large amounts of fluid can change loads on nearby rocks. Stresses that are already there can be set free by the changes brought on by changes in fluid pressures. But as I mention, it's very hard to model this.
Re: BBD
Unless the mini quake results in the release of CO2, in which case it will be difficult to hide the deaths it would cause.
It is interesting to contrast the tone of the article refererenced with the earlier one in April -
http://www.bbc.co.uk/news/uk-england-12930915
The USGS website earthquake maps don't bother to log anything less than 4.5.....
Walt Stone
But as I mention, it's very hard to model this.
Ah, perhaps for you or me, mere mortals, but the greater-than-gods "scientists" behind AGW will surely find a way and prove that the Earth will split in two if we frack the frecking gas.
Never underestimate a determined fanatic, Walt. I am certain that ZDB is writing a computer model as we speak. Haven't heard much from her, so that is what she must be up to.
According to WIkip -
magnitude less tha 2 are microquakes, which cannot be felt. (apparently a mag 0 quake is one producing a displacement of 1um at 100km). There are approx 8000 micro quakes per day worldwide.
Just missed a bullet there, didn't we?
Having lived through many earthquakes in the Silicon Valley over 30 years, I can say that you may notice a 3, but only if the building has weak floors and so bounce. It feels like a very large truck drove by outside. You will notice a 4, but it is over in a few seconds -- "Oh, gee, we're having an earthquake -- I think". A 5 everybody notices -- those stick around for perhaps 10 seconds. You hear those as well. First a crack, and then a shake -- "Earthquake!" Then you enjoy the ride. A 6 gets your attention - for about 20 seconds -- "OH GOD!" A 7 gets your undivided attention -- "OH, GOD! SAVE ME!" That was the Loma Prieta quake of October 17, 1989 which lasted about 45 seconds (I was there, it was not 15 seconds as some report). I was in a computer room being thrown back and forth between two large computers while sitting in a desk chair on wheels. As I bounced back and forth, I watched the two mainframes move slowly towards each other with me in between. Now that was interesting!
As for what happened in Japan last month I can only imagine in my worst nightmares.
Somehow I consider 4 and below not worth worrying about -- unless I am in a 100 year old brick building that could fall. So, as long as the fracking keeps it under a 4, I will be happy to buy the gas to heat my house.
Thanks, heading Out, Walt Stone and Chuckles for your information. Very helpful.
There have been loads of mini-quakes reported in the UK over the years as a result of deep coal mining. And loads more where coal mining wasn't implicated. There have no doubt been a few ceiling cracks, perhaps a broken cup and some dogs that started barking.
But this shale gas rig is drilling at over 2770m deep (compare the deepest coal seams ever worked in the UK at about a kilometer) and you aren't talking about a 300m long coal face collapsing perhaps 3m behind the face supports.
So despite Harrabin's efforts at trying to whip up a storm, I'll take some convincing that frakking will be a problem.
I also liked the BBC's efforts the other day, also trying to rubbish shale gas, when they pictured the drilling rig (NOT the gas well head) and painted a dreadful vision of these shale gas workings desecrating the landscape. Pretty rich for the Beeb, great cheerleaders for BigWind. And of course, it isn't easy to hide a wind farm, in fact turbines have to be as exposed as possible.
1.5! Now we really are surely having a joke! The UK has how many above this figure a year well before Fracking began?
Here is a nice little link showing what occurs every day around the Balkans and Med close to where I live!
http://www.sv1lh.net/aprs/weather/... They can be an inconvenience when they shake the head off the beer!
By the way Bish, as you are North of the border was the larger one in Scotland one day later (2.5) caused by fracking or you dropping the empty bottle?
http://www.earthquakes.bgs.ac.uk/
If "fracking" is helping to reduce underground stress by inducing minor earthquakes this would almost certainly be entirely beneficial.
Dangerous earthquakes occur because stress is allowed to build up over long periods without release. One of the strategies being investigated for reducing earthquake damage in California involves pumping liquids into the fault plane to encourage smaller progressive movements and prevent stress from building up.
I am surprised the BGS are so vocal on this. Perhaps they foresee some possible research funding implications?
Shale gas is a great hope for humanity, but poses a great challenge for the zero carbon enthusiasts. As we can already see, they will be very keen to find ways of trying to prevent it from ever being developed.
Just to back up Martin Brumby's point, Jacek Trojanowski, Head of Seismic Monitoring at the Institute of Geophysics, Polish Academy of Sciences, has pointed out that coal mining miniquakes are between 3 and 4 magnitude typically - we just call it subsidence. Odd how we used to protect coal mining despite this, while even the slightest implication of a fracking connection to microquakes (not even mini) is suddenly cause for concern.
Now can anyone show that wind turbines cause microquakes? That would be funny.
It sorta dawn me that those of you who have never experience a magnitude 3 earthquake that you merely need to get about 100 meters from one of those "green" wind turbines. You know, one of those monsters with 50 meter blades that kills dozens of migrating birds every year. Surely you have one in your back yard by now.
THUMP! THUMP! THUMP!
The ground actually shakes about as much. Try it.
guys...we are talking of politicians who have never done a day's work and whose parents have only ever been politicians. They do not know that stuff happens in he normal course of events.
Has someone been building a replica Nicola Tesla's "Earthquake Machine" again? Only 6 lb in weight and small enough to fit into a coat pocket. Poor old fracking could be blamed for everything!
I'd suspect UEA, but the way they operate it would weigh 300 kg and be operated by a committee paid for by a Government subsidy after extensive computer modelling to prove its feasibility.
At Kola in Russia, they drilled a world record depth research hole more than 12 km deep, at which depth the rocks were difficult to fracture with the drill bit. This drilling work was finished about 1994. It took 30 years.
There are many web sites reporting results, but this is a handy summary. I've read the massive book by the Minister for Geology at the time. From http://www.damninteresting.com/the-deepest-hole
"To the surprise of the researchers, they did not find the expected transition from granite to basalt at 3-6 kilometers beneath the surface. Data had long shown that seismic waves travel significantly faster below that depth, and geologists had believed that this was due to a “basement” of basalt. Instead, the difference was discovered to be a change in the rock brought on by intense heat and pressure, or metamorphic rock. Even more surprisingly, this deep rock was found to be saturated in water which filled the cracks. Because free water should not be found at those depths, scientists theorize that the water is comprised of hydrogen and oxygen atoms which were squeezed out of the surrounding rocks due to the incredible pressure. The water was then prevented from rising to the surface because of the layer of impermeable rocks above it.
"The Russian researchers were also surprised at how quickly the temperatures rose as the borehole deepened, which is the factor that ultimately halted the project’s progress. Despite the scientists’ efforts to combat the heat by refrigerating the drilling mud before pumping it down, at twelve kilometers the drill began to approach its maximum heat tolerance. At that depth researchers had estimated that they would encounter rocks at 100°C (212°F), but the actual temperature was about 180°C (356°F)– much higher than anticipated. At that level of heat and pressure, the rocks began to act more like a plastic than a solid, and the hole had a tendency to flow closed whenever the drill bit was pulled out for replacement. Forward progress became impossible without some technological breakthroughs and major renovations of the equipment on hand, so drilling stopped on the SG-3 branch. If the hole had reached the initial goal of 15,000 meters, temperatures would have reached a projected 300°C (572°F)."
Put bluntly, the prior wisdom misinterpreted the seismic results, the microfracture zone, the depth to basement, the geothermal gradient and the plasticity of the bottom rocks. The microfracture zone should cause a rethink of how some shallow earthquakes might be generated. If the microfracture is a burst, maybe it can cause an earthquake - it can happen anywhere where crust is descending, it does not hav to be near a fault or rift. Few have understood this. I doubt if the complex variation of pressure (of various types) with depth below 5 km is well understood by anybody, especially for shallow earthquakes. I would love to be referred to contrary evidence.
That site is aptly named Geoff, tks for that.
Bish, clearly fracking turns your Liver Black, just say NO! ;¬)
I thought it was caused by Eric Pickles riding on the'BIg One' at Blackpool Pleasure Beach.
And those of us who have lived in coal mining areas will have experienced Earth "quakes" from underground blasting and land movement caused by huge amounts of material extracted underground and tunnel collapse. Houses sink, walls crack, roads get potholes and cracks in them. Sometimes eerie noises are heard inside homes - ghosts - clanking metal, creaking woodwork, disembodied voices, ghostly laughter even. The miners working below.
Fracking causes underground tremors - so what. Nothing new.
"nuclear testing"
Now there's a thought. If they could do it in deep shale deposits in future, who knows how much gas might be released!
The testing of nuclear devices to release gas from tight deposits was called Gas Buggy and took place on December 10, 1967. I have some details here .
Thank you, HO - that's fascinating. I thought I was making it up!
It seems to work, though: "Following the blast, in 1970 and 1971, the companies burned off, or "flared," 430 million cubic feet of gas into the open sky".
Hard to think of anything better calculated to annoy the Greens. If I ever meet Caroline Lucas, I'll suggest it...
Take a look at Iceland:
http://en.vedur.is/earthquakes-and-volcanism/earthquakes/#view=map
they had 42 earthquakes yesterday - pretty typical.
What's the fuss about?