SMU-UT Study Shows 'Plausible' Connection Between DFW Quakes and Saltwater Injection Well

[OKIsItJustMe]

http://www.smu.edu/News/2010/dfw-earthquake-study-10march2010.aspx

SMU-UT Study Shows 'Plausible' Connection Between DFW Quakes and Saltwater Injection Well

Full report available in 'The Leading Edge' magazine website

March 10, 2010

DALLAS (SMU) — A study of seismic activity near Dallas/Fort Worth International Airport by researchers from SMU and UT-Austin reveals that the operation of a saltwater injection disposal well in the area was a “plausible cause” for the series of small earthquakes that occurred in the area between October 30, 2008, and May 16, 2009.

The incidents under study occurred in an area of North Texas where the vast Barnett Shale geological formation traps natural gas deposits in subsurface rock. Production in the Barnett Shale relies on the injection of pressurized water into the ground to crack open the gas-bearing rock, a process known as "hydraulic fracturing." Some of the injected water is recovered with the produced gas in the form of waste fluids that require disposal.

The earthquakes do not appear to be directly connected to the drilling, hydraulic fracturing or gas production in the Barnett Shale, the study concludes. However, re-injection of waste fluids into a zone below the Barnett Shale at the nearby saltwater disposal well began in September 2008, seven weeks before the first DFW earthquakes occurred and none were recorded in the area after the injection well stopped operating in August 2009.

The largest of the DFW-area earthquakes was a 3.3 magnitude event reported by the USGS National Earthquake Information Center.

...

[Ozymanithrax]

1. What I read was Smut study...but it is still an interesting article.

[DURHAM D]

2. I don't know about this. Who paid for the study?

I find it hard to believe that the salt water disposal was somehow more of a problem that the "fracturing". One activity is aggressive - the other is passive.

[OKIsItJustMe]

3. Looks to be self-supported, with help from the NSF and cooperation from the natural gas company

http://smu.edu/newsinfo/pdf-files/earthquake-study-10march2010.pdf

...

Following the October earthquakes, seismologists from Southern Methodist University (SMU) borrowed six, three-component, broadband seismographs from an NSF-supported instrument pool and operated them at sites in Tarrant and Dallas Counties (Figure 2) between 9 November 2008 and 2 January 2009. Although the NEIC reported no felt earthquakes during this period, the SMU stations recorded numerous local events, including 11 earthquakes between 20 November and 2 December with exceptionally well-recorded P and S arrivals on three stations, AFDAD, AFMOM, and CPSTX.

The present paper summarizes our analysis of seismograms of the DFW sequence and reports precise locations for 11 well-recorded but “non-felt” events. Using seismological data and other information available in the public record, we show that: (1) In 2008 prior to 29 October, we detected no earthquakes occurring near DFW, including earthquakes too small to be locatable by the NEIC; (2) the 11 hypocenters have a preferred focal depth of 4.4 km and lie along a 1.1 km SW-NE line; and (3) the mean epicenter estimate of the 11 events is less than 0.5 km from a 4.2-km deep saltwater disposal (SWD) well where injection began on 12 September 2008, seven weeks before the DFW focus became active. On the basis of time and spatial correlations, we conclude the DFW sequence may be the result of fluid injection at the SWD well, but we are puzzled as to why earthquakes occur at this particular location but not near other SWD wells in the region. Finally, we discuss the DFW earthquakes in the context of regional historical seismicity, which includes both natural and induced earthquakes. We observe that historical induced earthquakes in the Texas region have all been less than magnitude 4.6 and have not produced substantial damage.

...

Acknowledgments: We thank the Incorporated Research Institutions for Seismology (IRIS) instrument pool for providing the seismographs used in this study. We gratefully acknowledge discussions with scientists at Chesapeake Energy concerning regional geology, brine injection practices, and regional seismicity.

[kestrel91316]

4. But, but, Gawd says in the bible that nothing man does can affect the earth in any way.

[OKIsItJustMe]

5. Do you have a citation for that?

“The nations were angry; and your wrath has come. The time has come for judging the dead, and for rewarding your servants the prophets and your saints and those who reverence your name, both small and great—and for destroying those who destroy the earth.” (Rev 11:18)

[kestrel91316]

6. Well, well, but, where do the fundies get the cockamamie idea that

man is so piddly and insignificant that he CANNOT effect climate change through pollution with CO2?????

ARRRGGGHHHH, heads exploding!!!!!!!!

Oh, wait, they must have made that part up.

[OKIsItJustMe]

7. The same place other people do

Let's face it, those of us who feel that humanity can affect the climate are in the minority in the US.

http://bible.oremus.org/?ql=135246264

"The earth lies polluted under its inhabitants; for they have transgressed laws, violated the statutes, broken the everlasting covenant. Therefore a curse devours the earth, and its inhabitants suffer for their guilt; therefore the inhabitants of the earth dwindled, and few people are left." (Isaiah 24:5-6)

[Nihil]

8. Not surprising ...

... considering that the link had been confirmed back in the 1960s
(Denver quakes / Rocky Mountain Arsenal pumping).

:shrug: