Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

  1. Sep 3, 2016 #1

    Astronuc

    User Avatar

    Staff: Mentor

    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.
     
  2. jcsd
  3. Sep 3, 2016 #2

    fresh_42

    Staff: Mentor

    Could it been induced by fracking?
     
  4. Sep 3, 2016 #3

    Astronuc

    User Avatar

    Staff: Mentor

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

    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
     
  5. Sep 3, 2016 #4

    Borg

    User Avatar
    Gold Member

    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.
     
  6. Sep 3, 2016 #5

    fresh_42

    Staff: Mentor

    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.
     
  7. Sep 3, 2016 #6

    Astronuc

    User Avatar

    Staff: Mentor

    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.
     
  8. Sep 4, 2016 #7
    From your link:
    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:
    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.
     
    Last edited by a moderator: May 8, 2017
  9. Sep 4, 2016 #8

    davenn

    User Avatar
    Science Advisor
    Gold Member

    sorta like closing the barn door after the horse has bolted !! :rolleyes:


    Dave
     
    Last edited: Sep 4, 2016
  10. Sep 6, 2016 #9

    Astronuc

    User Avatar

    Staff: Mentor

    https://www.yahoo.com/news/state-emergency-oklahoma-earthquake-093614955.html [Broken]
    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.
     
    Last edited: Jun 30, 2017
  11. Sep 8, 2016 #10
    "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 gotta 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 in to 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....
     
    Last edited: Sep 8, 2016
  12. Sep 8, 2016 #11

    davenn

    User Avatar
    Science Advisor
    Gold Member

    I had posted this in post #8 in the thread :wink:



    it also comments that the quakes are more likely a result of waste fluid injection, rather than
    directly from fracking activities

    Dave
     
  13. Sep 28, 2016 #12

    Astronuc

    User Avatar

    Staff: Mentor

    https://www.usgs.gov/news/magnitudes-oklahoma-earthquakes-shift-upward
     
  14. Sep 28, 2016 #13

    davenn

    User Avatar
    Science Advisor
    Gold Member

  15. Oct 12, 2016 #14
    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.
     
  16. Jan 2, 2017 #15

    Astronuc

    User Avatar

    Staff: Mentor

  17. Jun 29, 2017 #16

    1oldman2

    User Avatar
    Gold Member

  18. Jun 30, 2017 #17

    Evo

    User Avatar

    Staff: Mentor

    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.
     
    Last edited: Jun 30, 2017
  19. Jun 30, 2017 #18

    1oldman2

    User Avatar
    Gold Member

    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. o_O (I see that article as being one shot fired in a very large conflict, thank you NASA/JPL):thumbup:
     
  20. Jul 16, 2017 at 9:31 PM #19

    1oldman2

    User Avatar
    Gold Member

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Mag 5.8 (upgraded from 5.6) Earthquake, Pawnee, Oklahoma
  1. Oklahoma earthquakes (Replies: 3)

Loading...