PSN-L Email List Message

Subject: Of possible intrest for Guy., Ak.
From: "Timothy Carpenter" geodynamics@.......
Date: Thu, 3 Nov 2011 15:33:21 -0400


The folks watching the quakes around Guy Arkansas may be particularly
interested in the first article which has a link to a report by the Oklahoma
Geological Survey.

Okla. quakes associated with fracking :
http://www.eenews.net/public/eenewspm/2011/11/02/1

Ohio quakes tied to gas extraction? :
http://www.post-gazette.com/pg/11305/1186592-84.stm

 

The following quote from the second article is a bit troubling given that
there were quakes, several years ago, near Denver and Cleveland that were
attributable to waste injection wells. 'Heidi Hetzel-Evans, a spokeswoman
for the Ohio Department of Natural Resources, said the agency stood by
regulations allowing the well operations. The agency has "not seen any
evidence that shows a correlation between localized seismic activity and
deep-injection well disposal," she said.'

 

This is from http://earthquake.usgs.gov/learn/faq/?categoryID=1
 &faqID=1

Q: Can we cause earthquakes? Is there any way to prevent earthquakes?

A: 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 use of reservoirs for water supplies. Most of these earthquakes were
minor. The largest and most widely known resulted from fluid injection at
the Rocky Mountain Arsenal near Denver, Colorado. In 1967, an earthquake of
magnitude 5.5 followed a series of smaller earthquakes. Injection had been
discontinued at the site in the previous year once the link between the
fluid injection and the earlier series of earthquakes was established.
(Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with
Deep Well Injection--A Report to the U.S. Environmental Protection Agency:
U.S. Geological Survey Bulletin 1951, 74 p.)

 

And this is from
http://geology.geoscienceworld.org/cgi/content/abstract/16/8/739

On January 31, 1986, an earthquake of Richter magnitude 4.9 occurred in
northeastern Ohio some 17.0 km south of the Perry Nuclear Power Plant (PNPP)
and 12.0 km south of the Calhio injection wells. Accelerometers on site at
the PNPP recorded accelerations as high as 0.19 to 0.23 g. Many instruments
tripped due to high-amplitude vibrations. Microearthquake networks have
recorded 16 microearthquakes within 5.0 km of the injection wells with focal
depths ranging from 1.0 to 3.0 km. A hydrological model of an anisotropic
reservoir 7.2 km wide and 18.4 km long indicates a pressure buildup of 5.3
MPa at the epicenter and 11.8 MPa at the injection well. The assumption of
an anisotropic reservoir is consistent with available geophysical and
geologic data. A pressure increase of 11.8 MPa, based on stress ratio
estimates in crustal rocks in the region, is more than sufficient to induce
failure to a depth of 5.0 km. Furthermore, brittle faults and extensive
fracture permeability within the basement rocks would allow for the
migration of pressure transients to hypocentral distances. The indicated
pressure buildup of 5.3 MPa at the epicenter may have been sufficient to
trigger the January 31, 1986, earthquake.

 

-Tim-

 

Timothy Carpenter

Commerce Twp., Mi  48382

248-363-4529

248-766-1629

geodynamics@...........

geodynamics@.......

 

The folks = watching the quakes around Guy Arkansas may be particularly interested = in the first article which has a link to a report by the Oklahoma = Geological Survey.

Okla. quakes = associated with fracking : http://www.ee= news.net/public/eenewspm/2011/11/02/1

Ohio quakes = tied to gas extraction? : http://www.p= ost-gazette.com/pg/11305/1186592-84.stm

 

The = following quote from the second article is a bit troubling given that = there were quakes, several years ago, near Denver and Cleveland that = were attributable to waste injection wells. ‘Heidi = Hetzel-Evans, a spokeswoman for the Ohio Department of Natural = Resources, said the agency stood by regulations allowing the well = operations. The agency has "not seen any evidence that shows = a correlation between localized seismic activity and deep-injection well = disposal," she said.’

 

This = is from http://earthquake.usgs.gov/learn/faq/?categoryID=3D1&faqID=3D1=

Q: Can we = cause earthquakes? Is there any way to prevent = earthquakes?

A: = 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 use of reservoirs for water supplies. = Most of these earthquakes were minor. The largest and most widely known = resulted from fluid injection at the Rocky Mountain Arsenal near = Denver, Colorado. In 1967, an earthquake of magnitude 5.5 followed a = series of smaller earthquakes. Injection had been discontinued at the = site in the previous year once the link between the fluid injection and = the earlier series of earthquakes was established. (Nicholson, Craig and = Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well = Injection--A Report to the U.S. Environmental Protection Agency: U.S. = Geological Survey Bulletin 1951, 74 p.)

 

And = this is from http://geology.geoscienceworld.org/cgi/content/abstract/16/8/739

On January 31, 1986, an earthquake = of Richter magnitude 4.9 occurred in northeastern Ohio = some 17.0 km south of the Perry Nuclear Power Plant (PNPP) = and 12.0 km south of the Calhio injection wells. = Accelerometers on site at the PNPP recorded accelerations as = high as 0.19 to 0.23 g. Many instruments tripped due to = high-amplitude vibrations. Microearthquake networks have = recorded 16 microearthquakes within 5.0 km of the injection = wells with focal depths ranging from 1.0 to 3.0 km. A = hydrological model of an anisotropic reservoir 7.2 km wide = and 18.4 km long indicates a pressure buildup of 5.3 MPa at = the epicenter and 11.8 MPa at the injection well. The = assumption of an anisotropic reservoir is consistent with = available geophysical and geologic data. A pressure increase = of 11.8 MPa, based on stress ratio estimates in crustal rocks = in the region, is more than sufficient to induce failure to = a depth of 5.0 km. Furthermore, brittle faults and extensive = fracture permeability within the basement rocks would allow = for the migration of pressure transients to hypocentral = distances. The indicated pressure buildup of 5.3 MPa at the = epicenter may have been sufficient to trigger the January 31, = 1986, earthquake.

 

-Tim-

 

Timothy = Carpenter

Commerce Twp., Mi  = 48382

248-363-4529

248-766-1629

geodynamics@...........<= /o:p>

geodynamics@.......


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