Mag 5.8 (upgraded from 5.6) Earthquake, Pawnee, Oklahoma

[Astronuc]

Oklahoma has been experiencing numerous small earthquakes (Mag 3-4 range) in recent years.

A Mag 5.6 earthquake in Pawnee, Oklahoma happened this morning.
http://earthquaketrack.com/us-ok-broken-arrow/recent
2016-09-03 12:02:44 UTC
36.429°N 96.923°W
6.6 km depth

That's somewhat unusual. Hopefully not a trend.

I'm sure it was felt in Oklahoma City and Tulsa areas.

 

[fresh_42]

That's somewhat unusual.

Could it been induced by fracking?

 

[Astronuc]

USGS webpage - https://www.usgs.gov/news/magnitude-56-earthquake-oklahoma

Could it been induced by fracking?

Good question, and I expect a lot of folks are wondering. At this time, I'm not sure, but I would doubt so. One would have to investigate the preponderance of injection wells in the vicinity, and whether or not there is indication that that activity had modified the region in such a way to induce earthquakes.

On the other hand, the quake is located near an kink in the Arkansas River (Big Bend / Big Hill area), so that may be indicative of past seismic activity. I'm wondering if this is an indicator of a potential larger event. It certainly bears watching.Here is some background on induced earthquakes.
https://profile.usgs.gov/myscience/upload_folder/ci2015Jun1012005755600Induced_EQs_Review.pdf
https://www2.usgs.gov/faq/categories/9833/3426

http://earthquake.usgs.gov/research/induced/myths.php

 

[Borg]

The news tonight stated that earthquakes over 3.0 in Oklahoma went from 2 per year before fracking to over 900 in 2015. Just a guess but there might be a connection.

 

[fresh_42]

I mean, if we leave the political point aside, there is still the physical. You pump a water-like fluid into rocky fissures, say 2000 m deep at about 70 °C. If the fluids get deeper, it's even hotter. Thus there is an expansion of the fluid which is exactly the situation which might (geologists say will) cause the Cumbre-Vieja on La Palma to burst one day.

 

[Astronuc]

Rather than speculate, one needs to look at available evidence. For example, what are the typical magnitudes and depths of induced earthquakes? Then, ask, are there any fracking/injection operations in the vicinity of the quake? Is there even an oil field there?

I found one oilfield in Noble county south of Marland, OK, but that is west of Sooner Lake, while the earthquake is east of Sooner Lake.
Ceres South Oil Field
Class: Oilfield
County: Noble County near
Latitude: 36.5119843
Longitude: -97.2233783

Two oilfields in Pawnee county are further east of the 5.6 Mag quake.

Cleveland Oilfield
Class: Oilfield
Town: Cleveland, ~30km east of Pawnee, while
County: Pawnee County
Latitude: 36.2878466
Longitude: -96.4822448

Lauderdale Oilfield (8 km SE of Cleveland
Class: Oilfield
County: Pawnee County
Latitude: 36.2620171
Longitude: -96.4211305

But are there any injection operations in those fields?

It's worthwhile considering the matter of induced earthquakes, but one has to be careful and collect evidence.

USGS has revised the depth from ~6.6 km to 4.5 km.

 

[zoobyshoe]

Rather than speculate, one needs to look at available evidence. For example, what are the typical magnitudes and depths of induced earthquakes? Then, ask, are there any fracking/injection operations in the vicinity of the quake? Is there even an oil field there?

But are there any injection operations in those fields?

From your link:

Fact 5: Induced seismicity can occur at significant distances from injection wells and at different depths.

Seismicity can be induced at distances of 10 miles or more away from the injection point and at significantly greater depths than the injection point.

http://earthquake.usgs.gov/research/induced/myths.php

But there is a wildcard that geologists don't understand:

From http://www.tulsaworld.com/earthquak...cle_bfd90706-b53a-5c0f-9a50-2a9c36efd019.html:

The volume of wastewater from oil and gas activities disposed beneath Oklahoma soil climbed 81 percent across six years, coinciding with the state’s seismic leap in earthquakes.

Even more notably, the wastewater injected into the state’s deepest geologic formation — the Arbuckle — has ballooned 141 percent during the same period.

The substantial rise in those volumes is documented in a https://www.researchgate.net/publication/288833796_Class_II_Saltwater_Disposal_for_2009-2014_at_the_Annual-_State-_and_County-_Scales_by_Geologic_Zones_of_Completion_Oklahoma?channel=doi&linkId=5685967f08ae1975839520d4&showFulltext=true by an Oklahoma Geological Survey scientist...

...Hydrogeologist Kyle Murray, who conducted the study, told the Tulsa World last week it is concerning that “very little” is known about the Arbuckle formation and how it may be hydraulically connected with the basement. The study is another piece needed to eventually solve Oklahoma’s earthquake puzzle...

...That data may be key to unlocking puzzling areas in which seismicity isn’t near deep or high-volume wells. An example of that is the recent 24-hour swarm of temblors near Fairview, with the vast majority of wells more than 10 miles away.

Geological Survey Director Jeremy Boak said there is a lot of variation in Grant, Alfalfa and Woods counties. He called the Fairview sequences a “curious anomaly” that scientists must closely inspect.

“There’s another earthquake zone that’s been sort of going on for some time now over in Woodward County, and we don’t know what’s going on there,” Boak said. “There’s only one Arbuckle injection well nearby, and it’s not a big-volume well.

“So there’s some activities that are going on that we clearly don’t understand. In general, we’re pretty confident that what we’re seeing is this relationship of seismicity to disposal, and disposal in the Arbuckle.”

So, generally speaking, you don't see earthquakes beyond ten miles from an injection site, except in the case of injections into this Arbuckle Formation, but for reasons not well understood.

 

[davenn]

(CNN)The Oklahoma Corporation Commission is telling operators to shut down 35 disposal wells that may have played a role in a 5.6-magnitude earthquake that shook at least six states Saturday, Gov. Mary Fallin said.
The disposal wells, which are linked to fracking and other industries that need to dispose of toxic waste water by injecting it deep into the earth, have recently drawn concern that they may actually induce earthquakes.

"This is a mandatory directive," Fallin said.
The commission, which regulates fuel, oil, gas, public utilities and transportation industries, is investigating to determine the epicenter of the quake that hit Pawnee, said commission spokesman Matt Skinner.
The Environmental Protection Agency is also investigating, Fallin said.

Read More
Skinner says earthquakes in Oklahoma are generally not directly caused by fracking, but rather by pressure from the disposal wells, which are used by the industry to get rid of the toxic waste water that comes out of the Earth along with oil and gas.
"The disposal wells dispose into the state's deepest formation, the Arbuckle formation, which is right above what we call the basement," Skinner said. The basement is above where the critical faults lie that shift and make earthquakes."
Those disposal wells within five miles of the 10-mile section of the fault in question are to be shut down within seven days, and all the other wells must be shut down within 10 days, Fallin said.

sorta like closing the barn door after the horse has bolted ! Dave

 

[Astronuc]

https://www.yahoo.com/news/state-emergency-oklahoma-earthquake-093614955.html
AP reports that "Oklahoma's Governor declared a state of emergency in Pawnee County, after Saturday's earthquake," and "37 wastewater disposal wells used by oil and gas producers are being shut down." It seems authorities will investigate the quake and try to determine if there was a link to wastewater injection.

 

[wild irish]

"Then, ask, are there any fracking/injection operations in the vicinity of the quake? Is there even an oil field there?"

Reference https://www.physicsforums.com/threads/mag-5-6-earthquake-pawnee-oklahoma.884053/

Answer: YES, the 5.6 quake was directly under an NG well head, and there are at least 4 Wastewater Injection wells within 5 miles of the epicenter... you just got to know WHAT to look for, and Google Earth clearly displays the visual evidence. the OCC has ordered the shutdown of 37 ACTIVE Injection wells in the area...
And exactly WHAT are they so worried about? The Cushing, Oklahoma storage facilities are 30 miles to the south... MILLIONS of barrels of crude oil are in those storage tanks at Cushing, and the TANKS were designed to withstand only a 5.5 mag. quake... there have been three 3.5-ish quakes a mile or so west of THE TANK FARMS in the last week or so... The tanks have been subjected to repeated seismic activity for years now... Metal fatigue will take it's toll, eventually... The Wastewater Injection wells nearest to the Cushing tanks were shuttered a couple years ago BECAUSE of the quakes they'd induced...
And "Wastewater Injection wells" are FRACKED before injection begins... the very process of injecting the waste is the SAME operation as "fracking", only the fluid is changed from pre-frack, to post-frack... Oh, and the pressures are about half, and the VOLUME/RATE is much higher during a disposal ... Disposal is done at a central point, too... so that increases the REALIZED pressure/strain change in the surrounding strata... FRACKING is done along a length of perforated well casing, over a variable distance(1/2 to 2 miles typical), in a horizontal well hole... Waste Injection uses a single outlet point, and is much deeper in the Earth than the oil/gas wells... the DEPTH of the injections increases strain buildup... and then, SNAP! Fracking also induces quakes, but they are typically lower in magnitude, and at shallower depths. FRACKING is a SMALL earthquake! it induces strain, then FRACTURES the strata... Rocks break, then "sand"(natural or ceramic) and fluids flow into keep the voids open... Therefore, in that way, it's worse than a similar magnitude earthquake. Larger magnitude quakes occur in the oil/gas fields when pre-existing faultlines become over-stressed by the fracking and injection operations...

 

[davenn]

"Then, ask, are there any fracking/injection operations in the vicinity of the quake? Is there even an oil field there?"

Reference https://www.physicsforums.com/threads/mag-5-6-earthquake-pawnee-oklahoma.884053/

Answer: YES, the 5.6 quake was directly under an NG well head, and there are at least 4 Wastewater Injection wells within 5 miles of the epicenter... you just got to know WHAT to look for, and Google Earth clearly displays the visual evidence. the OCC has ordered the shutdown of 37 ACTIVE Injection wells in the area...

I had posted this in post #8 in the thread
it also comments that the quakes are more likely a result of waste fluid injection, rather than
directly from fracking activities

Dave

 

[Astronuc]

The U.S. Geological Survey is updating the official magnitude of the September 3, 2016 Pawnee, Oklahoma earthquake to Mw 5.8 (from 5.6), making it Oklahoma’s largest recorded earthquake to date.

https://www.usgs.gov/news/magnitudes-oklahoma-earthquakes-shift-upward

Concurrently, the USGS is also updating the official magnitude of the November 6, 2011 Prague, Oklahoma earthquake to Mw 5.7 (from 5.6). Questions regarding their relative size prompted a re-analysis of both earthquakes. Both updates are the result of comprehensive studies of the long-period, globally-recorded seismic data for these earthquakes, using consistent approaches and datasets for each event.

 

[davenn]

https://www.usgs.gov/news/magnitudes-oklahoma-earthquakes-shift-upward

that helps to explain how it was felt over such a wide area

 

[CapnGranite]

http://geology.gsapubs.org/content/early/2016/10/12/G38275.1.full.pdf+html
Probabilistic assessment of potential fault slip related to injection induced earthquakes: Application to north-central Oklahoma, USA

ABSTRACT We utilize quantitative risk assessment (QRA) to calculate the conditional probability of slip on mapped faults in response to injection-related increases in pore pressure in northcentral Oklahoma (USA) where widespread injection of produced saltwater has triggered thousands of small to medium-sized earthquakes in the past 7 yr. The conditional probability incorporates the uncertainty in each Mohr-Coulomb parameter (stress tensor, pore pressure, coefficient of friction, and fault orientation) through QRA. The result is a cumulative distribution function of the pore pressure required to cause slip on each fault segment. The results can be used to assess the probability of induced slip on a known fault from a given injection related pore pressure increase. After dividing north-central Oklahoma into six study areas, we invert earthquake focal plane mechanisms in each area to constrain the orientation and relative magnitude of the principal stresses. The QRA identifies the potential for slip on the fault that produced the M 5.6 Prague earthquake in 2011 and the northeastern extension of a mapped fault associated with the M 5.1 Fairview earthquake sequence that occurred in early 2016, and, had the 289°-striking fault of the September 2016 M 5.8 Pawnee event been mapped, it would have been identified as potentially active.

This is the latest in a long list of papers on injection wells in the area. The papers has maps showing compelling effect of injection on movement along known faults. It's worth tracking down in a library.

 

[Astronuc]

One of the infographics on the fivethirtyeight relates fault lines, fracking (injection wells) and earthquakes in Oklahoma.

How The Oil And Gas Industry Awakened Oklahoma’s Sleeping Fault Lines
http://fivethirtyeight.com/features...stry-awakened-oklahomas-sleeping-fault-lines/

 

[1oldman2]

This just released.
NASA-led Study Examines Geology of Oklahoma's Largest Earthquake.
https://www.jpl.nasa.gov/news/news...._campaign=NASAJPL&utm_content=daily20170629-2

 

[Evo]

I'm glad this is finally getting attention, I had some time ago posted about fracking/waste water injection and Oklahoma earthquakes and told to shush, it was not related. I understand that injection wells are more damaging, but both are bad.

 

[1oldman2]

The NASA map tells an interesting story but the GIF of locations over time, that speaks volumes. It's too bad we live in the "Control/Alt/Delete" age, otherwise those Quakes might have really been related to the business in question. (I see that article as being one shot fired in a very large conflict, thank you NASA/JPL)

 

[1oldman2]

https://www.nature.com/articles/s41598-017-04992-z
"Our results suggest that the Pawnee earthquake is a result of interplay among injection, tectonic faults, and foreshocks."

 

[Astronuc]

7 earthquakes struck Oklahoma in 28 hours
http://www.businessinsider.com/oklahoma-earthquakes-why-2017-8?r=UK&IR=T

Much (but not all) of that wastewater injection is associated with the fracking boom, which has led the practice to become more common in recent years, especially in Oklahoma. Although the state isn't the only one experiencing a spike in wastewater injections, Oklahoma is full of eons-old fault lines that went quiet long ago. Wastewater operations seem to be shaking some of those faults loose, making the land especially vulnerable to earthquakes.

I heard a report a couple of months ago that geologists had correlated a rainfall (precipitation) with some earthquake activity in parts of California. Apparently, the reasoning has to do with groundwater (hydraulic pressure) activating some faults.

 

[Noisy Rhysling]

The news tonight stated that earthquakes over 3.0 in Oklahoma went from 2 per year before fracking to over 900 in 2015. Just a guess but there might be a connection.

Correlation proves causation?

Is 900 a completely unknown number of quakes/year?

 

[davenn]

Is 900 a completely unknown number of quakes/year?

for that region, yes ... a few dozen or so would most likely be the norm
probably difficult to find older records for pre fracking times. I will have a bit of a dig

 

[Borg]

Correlation proves causation?

As a general rule, no. However, this is way beyond any kind of statistical anomaly. Increased earthquake activity around fracking sites has been reported for years. I've read a few dozen articles on fracking and earthquakes and have yet to hear of a place where fracking is being done where an increase in earthquakes didn't follow.

And, then there's the fun side effect of flammable tap water that has occurred in the area of fracking sites. Probably just more coincidence.

From the articles that I've read, the playbook is usually the same for the oil companies - deny that there is a relationship, deny access to data that might prove a relationship, and attempt to discredit anything that implies a relationship.

 

[Noisy Rhysling]

for that region, yes ... a few dozen or so would most likely be the norm
probably difficult to find older records for pre fracking times. I will have a bit of a dig

It was a bit rhetorical. We would not know if that level of activity had never happened, ever, in the area. The sample size is too small.

That's only for recorded quakes, of course. The geology of the area does or does not preclude clusters of quakes by other means in the 900+ level? (Just wondering.)

 

[Borg]

From USGS:
Induced Earthquakes

https://earthquake.usgs.gov/research/induced/myths.php.

 

[davenn]

It was a bit rhetorical. We would not know if that level of activity had never happened, ever, in the area. The sample size is too small

not true ... there is a good seismic network across the USA ... maybe not never, but considering the significant increase in activity since man's intervention, it's very reasonable to assume 1+1 =2

That's only for recorded quakes, of course. The geology of the area does or does not preclude clusters of quakes by other means in the 900+ level? (Just wondering.)

huh ? not sure what you are getting at there ... are you inferring there are 100's of events that are not being recorded
if so ... then again, not true

Dave

 

[Noisy Rhysling]

not true ... there is a good seismic network across the USA ... maybe not never, but considering the significant increase in activity since man's intervention, it's very reasonable to assume 1+1 =2
huh ? not sure what you are getting at there ... are you inferring there are 100's of events that are not being recorded
if so ... then again, not true

Dave

The sample size is small considering the amount of time Kansas has been above water. I don't doubt the 900 number, just the uniqueness of it.

 

[AVS]

Good thing fracking is releasing all these stresses or we could be in for a really big earthquake down the road

 

[Noisy Rhysling]

Good thing fracking is releasing all these stresses or we could be in for a really big earthquake down the road

"Paging unexpected consequences."

 

[Ophiolite]

Good thing fracking is releasing all these stresses or we could be in for a really big earthquake down the road

I considered posting a similar remark, but refrained since it may not be valid. Low frequency earthquakes, sometimes called slow earthquakes and prior to that, I believe, silent earthquakes can relieve stresses over hours, or days, rather than minutes. The energies involved can be substantial, but because they are dissipated over a much longer time period damage is non-existent and detection is difficult.

From my limited reading on the subject these seem to be associated with subduction zones rather than the "stable" interior of continents, but then most research focuses on subduction zone earthquakes. If slow earthquakes are a feature of areas such as Oklahoma then the fracking is initiating conventional earthquakes that might not otherwise occur.