UPDATE: I had to change the title of this post because we are way past six earthquakes now.
My inbox overfloweth with earthquake notices from Oklahoma last night.
Some of the notices may be duplicates of the same event. I’m not sure.
3.3M Event Page (same event number as the 2.7M event above)
Wow! Oklahomans, hang in there!
Recently the Oklahoma Geological Survey found that fracking may have caused some of the earthquakes. Here is the report: Examination of Possibly Induced Seismicity from Hydraulic Fracturing in the Eola Field, Garvin County, Oklahoma
UPDATE: This just in…
UPDATE: From the comments…
5.6M Event Page – we felt this one here north of Dallas and someone in Decatur reported feeling their house shake. It was even felt in Grand Prairie.
UPDATE: And another one…
UPDATE: The title for this post is no longer appropriate. While we were sleeping, Oklahoma continued to have earthquakes. I have a spreadsheet that shows the earthquake activity since 1990 from a square area that includes Texas, Oklahoma, a teeny bit of New Mexico and Mexico. Notice the recent dramatic spike.
Obviously, this graph does not include the most recent earthquakes in Oklahoma. I am working on plotting all the quakes on a map that is color coded by year. It’s a striking visual.
Now for list the latest activity:
3.2M Event Page
3.4M Event Page
4.0M Event Page
3.9M Event Page
3.2M Event Page
2.7M Event Page
3.0M Event Page
The comments on this post from an oil field worker are enlightening. I advise everyone living in a Gas Patch anywhere in the world to go outside now and take pictures of your foundation. Take pictures every week. This might provide some documentation about the shape of your foundation prior to fracking earthquakes. I don’t know about other areas but Texans cannot get earthquake insurance so you are on your own.
4.0M Event Page
3.7M Event Page
3.3M Event Page
Also see Industry literature admits that fracking can cause earthquakes.
UPDATE: another one…
2.8M Event Page
UPDATE: Dammit!
4.7M Event Page
See interesting comment at end of this post. Also–I’ve posted this before but if you are a new reader you have missed a lot–James Northrup says fracking is like blowing up bombs underground.
Another UPDATE: U.S. Government Confirms Link Between Earthquakes and Hydraulic Fracturing
About Sharon Wilson
Sharon Wilson is considered a leading citizen expert on the impacts of shale oil and gas extraction. She is the go-to person whether it’s top EPA officials from D.C., national and international news networks, or residents facing the shock of eminent domain and the devastating environmental effects of natural gas development in their backyards.
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Anonymous says
That earthquake was felt for hundreds of miles around (oklahoma, Texas, you name it). Fracking?? Haha. The earth has been around for a long time, and tectonic plates shift. Earthquakes have occurred for millions of years. Get over it.
PS- Oklahoma had over 1,700 earthquakes from 1977-2005.
A Texas Bluebonnet says
No wonder you listed yourself as anonymous. You insult our intelligence.
Texas Bluebonnet
Jason Drew says
You might want to add a 5.6 to the list. Are there any known fracking operations near Sparks, OK?
http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usb0006klz/
TXsharon says
Wow! I hope everyone is okay.
TXsharon says
I actually felt that quake. I live N. of Dallas. Just before 11:00 as we were watching a movie I felt like my chair was vibrating. I told my son to stop the movie and we were still for a few minutes. It was weird.
John B says
There is very limited fracking activity in Lincoln County, OK, only ~45 horizontal wells drilled in the last 2 years. That’s peanuts compared to N. Texas. This (eastern OK) is an active seismic area and has been for many years.
TXsharon says
There are over 100 injection wells within the vicinity of the earthquakes.
Noah Easton says
Yeah except for the correlation between fracking and earthquakes being inconclusive. Even if there is a level of causation between fracking and earthquakes, the documented cases had a maximum magnitude of 2.8. The recent quakes in Oklahoma have been significantly higher than 2.8 — something along the lines of 3 orders of magnitude higher — and occurred on a known fault line. Not to mention the huge amounts of energy that was released by these earthquakes, adding up to be an equivalent amount of energy released by a low yield nuclear weapon. Really think that oil companies are putting THAT MUCH hydraulic pressure into the ground?
TXsharon says
Actually, there are documented quakes caused by drilling that are much higher then 2.8. Google a little more and maybe you will find the study conducted by industry. If not, just be patient and I’ll post it soon.
Joern Krueger says
Take a look at this german article (Google Translate) about a study on earthquakes which are linked to conventional gas drilling.
Fracking is done in this area for 50 years now (only 300 times in whole germany), but the main problem seems to be the gas drilling itself and the massive disposal wells in this area.
http://www.spiegel.de/wissenschaft/natur/0,1518,407061,00.html
TXsharon says
Thank you for this, Joern.
Texas Bluebonnet says
Wonder if this article is available in Englsh. Many German news sources are. What about this one?
Thanks.
TXsharon says
I couldn’t find it in English and I looked but not too thoroughly.
me says
liar
Mike H. says
Note that the 5.6 magnitude earthquake is only 3.1 miles deep, within the reach of drilling & injection activities.
Induced seismicity in Colorado from an injection well:
http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6495005
Noah Easton says
As far as I know there are not any fracking operations near Sparks. Note that I am not debating that the wisdom of using fracking should be reexamined — it is definitely questionable environmentally. The thing is though, just because it is possible that fracking causes small earthquakes does not mean that it causes large earthquakes.
“That process can cause very small earthquakes, but the fracking process doesn’t really, we think, induce large earthquakes,” USGS scientist Mike Blanpied said on a video chat. “The thing that can induce larger earthquakes is the high-pressure waste fluid injection that’s done in some places.”
There seems to be an issue with bloggers claiming that an earthquake is caused by fracking if drilling occurred within several miles of an earthquake epicenter (not necessarily this blog, by the way. Just an observation that I have made in general). Sometimes an earthquake is just an earthquake. The previous record holder for strongest earthquake in Oklahoma in 1952 as well as a string of other earthquakes in the following years certainly weren’t caused by fracking.
TXsharon says
I guess I would be one of the bloggers you reference because, while I don’t believe every earthquake is caused by drilling, I believe a dramatic increase in earthquakes in an area where drilling has increased is an indication that drilling is causing or contributing to the earthquakes. I base my belief not on what some guy says on the TeeVee but on the studies I’ve found and common–cause and effect–sense.
Industry has a study that determined that drilling caused some pretty big quakes–7.3M.
Noah Easton says
So you’re telling me that industry has a study that determined that drilling caused an earthquake that released nearly 4 times the energy released by the Loma Prieta earthquake? That it caused an earthquake that has only been equaled or surpassed in magnitude in the contiguous United States 4 times in the past 100 years?
TXsharon says
I am telling you that industry has a study that hydrocarbon production can cause seismic activity and some of that activity has been “severe.” That is exactly what I’m telling you.
NEWS FLASH: This is NOT new news.
Noah Easton says
Well I have now had the pleasure of reading the study which you so gladly reference. First of all — the study by ‘Industry’ did not determine that drilling caused the Gazli earthquakes. Second, it references Soviet articles that at best show correlation, and the topic is not nearly as cut and dry as you seem to think. For example another scholarly article states the following.
“The surrounding region [Gazli] had been assigned a low seismic risk based on recent patterns of seismicity. Historic records from the ancient city of Bukhara show that earthquakes in the magnitude range 6 to 7 had actually occurred in the region several times prior to the turn of the century.”
TXsharon says
Well, I guess you are right then. Drilling and fracking don’t cause earthquakes–in your world.
TXsharon says
Oh, and you might want to check around because there are plenty of other studies and reports that confirm induced seismicity from hydrocarbon production. It’s pretty basic science, you know.
Kenneth Gardner says
So, the logic that larger earthquakes are not caused by the same fracking that causes smaller earthquakes would tell us then that if the oil light comes on our car, then when the engine seizes and junks the entire car, it was not because we were any lower on oil?
Stan Sitwell says
Has anyone really been far even as decided to use even go want to do look more like?
R.D. says
Great analogy, Kenneth! I’ve also been amazed at the recurring and illogical argument that something that’s been demonstrated to cause lower-level seismic activity couldn’t possibly be blamed for 5.6 or 4.7 quakes. Maybe fracking isn’t the ONLY cause, but I don’t see how you can deny that it is contributing to this uptick in quakes.
Learn to read, Stan. Kenneth’s comment makes perfect sense.
bigcitylib says
Any clear correlation between the the graph and recent increases in shale gas extraction?
Astrelfrog says
Show me the data. People have been drilling Oklahoma since it became a state. I’m not unsympathetic to the frackers, but OK does have geological reasons for quakes.
TXsharon says
People have not been doing high-impact, horizontal drilling and slick water high pressure fracking since Oklahoma was a state. This kind of drilling is quite different than what has happened previously.
Ah… the graph is actually data. Also there are some recent opinions, studies, reports that link fracking and injection to earthquakes.
It’s very simple physics actually.
Jane Lynn says
My husband felt a vibration/tremor while sitting in the living room chair around 11 p.m. last night. It lasted about 10 seconds. We are in southeast Arlington.
Mike H. says
This quake was felt from eastern New Mexico to Austin TX to MS to Springfield IL to Des Moines.
http://earthquake.usgs.gov/earthquakes/dyfi/events/us/b0006klz/us/index.html
Use the zoom out map.
S. A. Linden says
I’ve been following the possible fracking/quake connection for months now. First, Guy, Arkansas and the surrounding area show a distinct correlation w/ fracking disposal wells, in that the quakes increased steadily during active fracking (and scared the bejesus out of residents). When certain disposal wells were shut down as a result of complaints, I continued to monitor the natl. earthquake site daily and the rate of reduction of those quakes was predictably decreasing correlative to the well extinction. It’s taken months, but now you see a quake only once in a while, but always centered around Guy, AR. Logic would tell you that either (1) fracking disposal wells directly induced these minor quakes; or (2) the energy co. geologists made a bad mistake to begin with in recommending drilling over an already active seismic area.
“Minor” quakes leads to my other comment: who’s to say that a series of so-called minor quakes can’t ultimately destabilize an area geologically as much as occasional stronger quakes? You stress the seams of a bridge, or a ship, or countless other structures long enough and it will most certainly have a cumulative effect. Can geology be that much different? “Thinking” that a thing might not happen — that the risk is small — BTW, is NOT good science, and IS poor risk management.
TXsharon says
I wish I had a like button on the comments because I sure like yours. And I love that last sentence!
Julie Henry says
The earthquake early Saturday morning was a mere grumble that I slept through. I only awoke because I heard my husband say, “Holy Crap.”
Saturday night’s earthquake was quite another matter. I heard the rumble first, thinking it was a car with a boom box. Seconds later the house started shaking, my wheeled desk chair started moving and when I put both feet on the floor, the floor was moving. I looked over at my husband who was sitting up in bed and the bed was moving. (He was eating dinner and refused to be disturbed as I ran for a doorway).
We have hairline cracks in the ceiling, a few paintings on the walls askew and rattled nerves, but that seems to be the extent of it.
As to the cause, we do have a drilling outfit not far from our neighborhood, but I doubt it has any impact. There is probably some causal link between fracking and the recent increase in seismic activity, but it has yet to be proven. (Can you say “global warming”?) I am more inclined to want to see documentation of recent HAARP activity and it’s link to our recent earthquake and bizarre weather patterns.
mMark Brewer says
The possibility of severe earthquakes being triggered by a fracking quake is certainly within reason. The rock strata serves to support the adjacent layers. When a failure occurs it is possible that something as small as a sinkhole to as large as Reelfoot Lake or even larger can occur. In a summary found on the cause of the massive quakes associated with the New Madrid system ,the USGS seismologists described these quakes as being caused by the collapse of the underlying strata. That being said, the next logical question is “Is it really sound reasoning to allow any fracking or disposal drilling any where within a site so seismically active?” Some things are clearly not worth the risk. The energy industry has no conscience and has repeatedly proven its loyalty only to the dollar and has been notorious for letting John Q. Public pick up the tab.
Albert Campbell says
You might try reading the BIBLE about end times, It tells you about earthquakes.
Oklahoma Libertarian says
Shut up.
InNane says
There is a lot of worry in Pennsylvania in re: fracking. The state has a complicated geological history and there are lots of ancient faults and fractures. Any geoscientist knows that fluid injected at depth can lubricate and existing fault and result in an earthquake. My worry is for groundwater. When you start creating more fractures along which water (and gas) can migrate, how can you insure the integrity of an aquifer. What has been the groundwater impact (if any) in TX?
FrackingCrazy says
What you read,
What you test,
and what TCEQ tells you about the water in Texas, are 3 different scenarios.
The ground water is fracked! From everything from Methane, Hydrogen Sulfide to 2-BE, to lots of radioactive material.
Soon the contaminated water of NT will float to Edwards Aquifer where the paid for by Gashole politicians will fill up their glasses with NT contaminated water, and I will feel my sweet reward.
That’s mean…I know, but then, maybe then, the policies for oil and gas will change.
mMark Brewer says
There should be a vigorous investigating as to the real impact that fracking has on the ecology .But given the political muscle weilded by the energy companies we may have to wait until as the Bible says ” God will bring to ruin those ruining the earth”. Rev. 11;18
Mike H. says
“There are 181 injection wells in the Oklahoma county where most of the weekend earthquakes happened, said Matt Skinner, spokesman for the Oklahoma Corporation Commission, which oversees oil and gas production in the state and intrastate transportation pipelines.”
“But natural gas companies claim there is no proof of a connection between injection wells and earthquakes, and a study released earlier this year by an Oklahoma Geological Survey seismologist seems to back that up. It found most of the state’s seismic activity didn’t appear to be tied to the wells, although more investigation was needed.”
http://news.yahoo.com/big-quake-follows-increase-oklahoma-rumblings-203947305.html
Anonymous says
Maybe they’re taking all our Barnett Shale contaminated water to OK for disposal to keep things calmer here. Rick Perry can’t have any more earth movements than he can create all by his big self. Does he really think he can be president??
Noah Easton says
Okay so I am also wondering where you acquired your data about the number of earthquakes? In Oklahoma alone there were at least 30 earthquakes in 2001, whereas your chart only displays 2 earthquakes in Oklahoma and Texas combined. It looks like the criteria for what was put on the chart changed between 2001 and 2010, because while visually striking, a one hundred fold increase in number of earthquakes within 10 years is highly unlikely.
TXsharon says
I’m pretty sure you can read where I got the data under the graph.
You said:
“…a one hundred fold increase in number of earthquakes within 10 years is highly unlikely.”
Exactly!
Noah Easton says
So what happened to the other earthquakes in 2001, 2002, etc? Like I said, in Oklahoma alone there was 30+ earthquakes in just about every year — even the years in which you show only 2.
TXsharon says
Ask the USGS. It’s their data.
Maybe the quakes were below the level of 2.0. Regardless, the increase is dramatic.
Noah Easton says
Yeah I even checked the USGS database. Definitely more than 2 earthquakes, and definitely more than magnitude 2.
Noah Easton says
Can you post your search parameters? I’m unfortunately having trouble finding results similar to yours.
TXsharon says
It’s not easy to search the USGS site and get useful data. I had one of our scientists do the search for me using lon-lat. She did a square area around TX which would include most of OK except that little sliver at the top.
Wouldn’t it be nice if some geologists would do a real study without industry influence? I do know a few geologists at a university who are not under any industry influence and they can’t get any funding. All the funding comes from industry. Still, they have a great deal of evidence about how harmful this process is and about subsidence and when injection causes the earth to rise (can’t remember that term right now).
Corporate funding of Marcellus Shale studies at universities raises alarms
Read more: http://www.post-gazette.com/pg/11311/1188150-503.stm#ixzz1d7nC3bDU
Pat Hansard says
“There are 181 injection wells in the Oklahoma county where most of the weekend earthquakes happened, said Matt Skinner, spokesman for the Oklahoma Corporation Commission, which oversees oil and gas production in the state and intrastate transportation pipelines.”
http://nbcsports.msnbc.com/id/45180813/ns/sports/
Yeah, weird web address for this article.
D.Dunc59 says
I’ve been in the oil and gas bussiness for a number of years. I am not a spokes person for anyone,but I have observed alot of fracs and the aftermath thereof. Here is my question.Is it from the fluids and gases being injected during disposing and fracing or is it from the pressure being relieved great distances underground,because gas and oil is in deposits and are pooled up in the earth’s layers and gas travels through the shale, sand,or some other porious formation or a combination of both?
TXsharon says
I posted some diagrams here http://www.texassharon.com/2011/11/06/industry-literature-admits-fracking-can-cause-earthquakes/ And there is a link to an industry study you might find interesting.
You probably know a lot more about what might be causing stresses and imbalances than I do. But I think it is probably all of the above.
Mike H. says
That 4.7 magnitude aftershock was felt over a wide area as well:
http://earthquake.usgs.gov/earthquakes/dyfi/events/us/b0006lpf/us/index.html
D.dunc59 says
Okay park your SUV,turn off some lights and all this high tech gadgetry (that requires electricity)that we seem to not be able to live without. Or deal with a little ground shaking.Another question. The USGS predicted that the New Madrid fault has built up enough energy to slip and cause another sizable earthquake. Whose to say that this quake and all the others are not setting the stage for that big quake?
TXsharon says
I agree that we should park the SUVs and turn off the electricity but just because we are electricity users does not mean we have to put up with fracking and all the negatives it brings and it certainly doesn’t mean we can’t advocate for better and safer methods.
Dutch says
The earthquakes are a plus for them, {Releases more gas and makes their injection more effective}. They will continue to to deny that while the danger and damage increases.
JD Oklahoma says
I’ve been watching two things this week. The helicorder for the local station about 8 miles from here and the RSS feed from USGS for M +1 earthquakes worldwide.
I thought maybe USGS has some sort of threshold on this, but quakes from California pour in all day all the way down to M 1.0
Yet, I see activity on the local readout that is easily M 1.0 or greater and they don’t report it. Even a day or so after. So is the USGS “hiding” earthquakes around known injection well/fracking sites?
Here is another thing I’ve noticed. Worldwide most earthquakes are anywhere from 10 to hundreds of kilometers down, yet all of the quakes we’ve had in Oklahoma are at the same depth each time, around 5 Km.
Can anyone provide a scientific or geological explaination?
Robert Finne says
Man, they really come out of the woodwork to argue that they cannot POSSIBLY be causing earthquakes.
We went through the same thing the last few years in Arkansas and got the same reaction from the industry cheerleaders.
It was determined by AGS and CERI that 4 injection wells showed a direct correlation between seismic activity and well injections. The wells were closed and seismic activity dropped by over 75% immediately.
I attended a STRONGER rule review in Arkansas yesterday. Earthquakes and injection wells were a hot topic. One of the reviewers asked AOGC director Larry Bengal where the fluid that we used to inject was being disposed of.
SURPRISE!
His answer was it was now being trucked to Oklahoma and put into their injection wells.
TXsharon says
Oh my! See, I blogged about how they will have to find somewhere to put the massive amounts of waste. Ship it to Oklahoma worked for a while. Next up they will make housing material out of it.
I wanted to drive up for the STRONGER review but I’ve been rather busy.
jadedANDcynical says
Oh boy, is this going to be fun…
Lets take a look at the two “signficant” (as listed on the USGS PAGE) quakes, shall we?
“Magnitude 4.7
Date-Time Saturday, November 05, 2011 at 07:12:45 UTC Saturday,November 05,2011at 02:12:45AM at epicenter Time of Earthquakein otherTimeZones
Location 35.553°N, 96.748°W
Depth 4 km (2.5 miles)
Region OKLAHOMA
Distances 33 km (20 miles) NE of Shawnee, Oklahoma 67 km (41 miles) W of Okmulgee, Oklahoma 68 km (42 miles) SSE of Stillwater, Oklahoma 75 km (46 miles) E of OKLAHOMA CITY, Oklahoma
Location Uncertainty horizontal+/- 11.8 km (7.3miles);depth +/- 2.8km (1.7miles)
Parameters NST=148, Nph=151, Dmin=24.5 km, Rmss=0.85 sec, Gp= 25°, M-type=body wave magnitude (Mb), Version=C
Source Magnitude: USGSNEIC (WDCS-D) Location: USGSNEIC (WDCS-D)
Event ID usb0006k8b”
And
“Magnitude 5.6
Date-Time Sunday, November 06, 2011 at 03:53:10 UTC Saturday,November 05,2011at 10:53:10PM at epicenter Time of Earthquakein otherTimeZones
Location 35.537°N, 96.747°W
Depth 5 km (3.1 miles)
Region OKLAHOMA
Distances 8 km (5 miles) NW (317°) from Prague, OK 10 km (6 miles) SE (141°) from Sparks, OK 14 km (9 miles) ENE (72°) from Meeker, OK 72 km (44 miles) E (85°) from Oklahoma City, OK 304 km (189 miles) N (1°) from Dallas, TX
Location Uncertainty horizontal+/- 10.5 km (6.5miles);depth +/- 2.8km (1.7miles)
Parameters NST=189, Nph=192, Dmin=26.7 km, Rmss=1.06 sec, Gp= 29°, M-type=centroid moment magnitude (Mw), Version=C
Source Magnitude: USGSNEIC (WDCS-D) Location: USGSNEIC (WDCS-D)
Event ID usb0006klz”
Pay special attention to both the reported and uncertainty of the depth.
The http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usb0006k8b/ (4.7) took place 2.5 ± 1.7 miles down. The http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usb0006k8b/ (5.6) was 3.1 ± 1.7 miles down. This puts them in the range of .8 to 4.5 miles and 1.4 to 4.8 miles down respectively. The lower limit for each of these two quakes is well within the depth reached by fracking.
Is this incontovertable proof that these quakes are fracking related?
Not necessarily, but a correlation is strongly suggested.
To say that there is no way that fracking can cause earthquakes is ignorance at best and purposeful misdirection at worse.
What’s more:
I direct you to http://esd.lbl.gov/research/projects/induced_seismicity/ the Department of Energy’s website dedicated to Induced Seismicity. You are familiar with the DOE, yes?
“What causes Induced Seismicity?
Although research is still being carried out on the detailed causes of induced seismicity, there are many different applications which have been associated with induced seismic activity.
…
Therefore, that is why in many cases induced seismicity is caused by injecting fluid into the subsurface or by extracting fluids at a rate that causes subsidenceand/or slippage along planes of weakness in the earth. ”
Now, this next part deals specifically with fracking and, I must admit, seems to indicate that the potential risk is minimal:
“Another type of induced seismicity is that which is associated with “hydrofracturing”. Hydrofracturing is done by injecting fluid into the subsurface to create distinct fractures in order to link existing fractures together in order to create permeability in the subsurface. This is done to extract in situ fluids (such as oil and gas). Hydrofracturing is distinct from many types of shear induced seismicity because hydrofracturing is by definition only created when the forces applied create a type of fracture called a tensile fracture, creating a “driven” fracture. Shear failure has been observed associated with hydrofracturing operations, as the fluid leaks off into existing fractures, but due to the very high frequency nature of tensile failure (seismic source at the crack tip only) only the associated shear failure is observed by microseismic monitoring . However, hydofracturing is such a small perturbation it is rarely, if ever, a hazard when it is used to enhance permeability in oil and gas or other types of fluid extraction activities. To our knowledge hydrofracturing to intentionally create permeability rarely creates unwanted induced seismicity large enough to be detected on the surface even with very sensitive sensors, let alone be a hazard or an annoyance. In fact the very small seismic shear events created from the shear failure associated with the hydrofracture process are used to map the location of the induced permeability and as management toll to optimize fluid production. If not for the very small shear events it would be much more difficult to understand the effect of hydrofracturing because the seismic energy created from the “main fract” is to low to be detected, even from he most sensitive instruments at the surface of the earth Figure 3 is an example of how seismicity is used to map these hydrofractures. Last but not least another reason that the seismic risk is so low associated with hydrofracture operations in that they are of relatively low volume and short durations ( hours or days at the very most) compared to month and years for other type of fluid injections described above.”
OK, small quakes are not so bad, right? We’ve no reason to be concerned because the range of quakes produced is too small to be damaging.
what is concerning is the effect all of these small quakes may have in the http://www.cusec.org/earthquake-information/new-madrid-seismic-zone.html “NMSZ,” which could trigger a larger quake.
Whether the fault that ruptured in 1811-12 does so once more or another yet-to-be-defined fault breaks and generates a M 7+ quake, the truth is we would all be in a world of hurt.
http://arxiv.org/abs/physics/0407018 “Importance of small earthquakes for stress transfers and earthquake triggering” Is a study published on the http://arxiv.org/ Cornell University Library database which indicates just that possibility:
“The stronger the spatial clustering, the larger the influence of small earthquakes on stress changes at the location of a future event as well as earthquake triggering. If earthquake magnitudes follow the Gutenberg-Richter law with b>D/2, small earthquakes collectively dominate stress transfer and earthquake triggering, because their greater frequency overcomes their smaller individual triggering potential.”
This is telling us that even though each individual quake represents only a small amount of energy release, the cumulative effects are more than the sum total. In other words there is a possible synergistic effect with a multitude of small quakes on a (non) related fault system within a certain geographical area.
Why hasn’t this been given more research?
“Because large earthquakes modify stress over a much larger area than smaller ones, and because computing Coulomb stress changes requires a good model of slip distribution available only for large earthquakes, most studies have neglected the influence of “small” earthquakes.”
So, how does this influence propagate into a fault system?
“• A triggered earthquakes size is independent of the magnitude of the triggering event (“mainshock”) as suggested by [Helmstetter, 2003]. This implies that the crust is everywhere close to failure, such that any small earthquake, triggered by a previous small one, can grow into an event much larger than its trigger”
As one takes notice of the rifts that circle the globe and then thinks about the fact that there is spreading taking place around the globe, one cannot help but conclude that all of the that spreading is going to be causing pressure to increase in areas which are being “crowded.” This results in a globe who’s surface is everywhere fractured, thus on the point of rupture at any given time with no prior notice.”
What does all of this mean?
“These results imply that a small earthquake can trigger a much larger earthquake. It thus validates our hypothesis that the size of a triggered earthquake is not determined by the size of the trigger, but that any small earthquake can grow into a much larger one [Kagan, 1991b; Helmstetter, 2003; Felzer et al., 2004]. The magnitude of the triggering earthquake controls only the number of triggered quakes.”
So, smaller quakes can trigger larger quakes and it is merely the number of quakes triggered, not size of subsequent quake which is affected when considering remote triggering.
It all boils down to this:
“Although large earthquakes are much more important than smaller ones for energy release, small quakes have collectively the same influence as large ones for stress changes between earthquakes, due to seismic spatial clustering.”
Since smaller quakes occur in a more compact area, they have influence equivalent to larger quakes due to the closer proximity to one another.
This means, that all of the fracking induced quakes that are taking place are acting like a series of firecrackers popping off continually on top of a larger fault system (NMSZ) and are potentially going to cause that system to release any pent up energy.
Remember, it’s not the fact that it’s an earthquake, or volcano (seems to be a bit of activity on that front around the world presently), but it is more a function of energy that is being released and thus moved to another location. Which causes a build up of stress (energy in potential) increasing until friction is overcome (a rupture happens) and then that energy flow is unblocked, albeit briefly, and thence the energy seeks a new equilibrium.
Anonymous says
Here’s a great earthquake monitor. Virginia is in denial along with Oklahoma. It’s injection wells in Virginia as well.
http://folkworm.ceri.memphis.edu/recenteqs/Quakes/quakes0.html