Here's a very interesting research finding for the people in Oklahoma and other areas of the world who are injecting wastewater for oil and gas exploration. We don't know much about this, but USGS is the authority on Geology and work with scientists around the U.S. (and the world). People who experience earthquakes in areas where this fossil fuel activity is happening should take note, especially if you start experiencing earthquakes.
For more information from another source, visit CA Frack Facts: http://www.cafrackfacts.org/impacts/water/
SCIENCE NEWS: Reawakened Oklahoma Faults Could
Produce Larger Future Events
Reactivated
faults that have produced thousands of Oklahoma earthquakes are capable of
causing larger seismic events, according to U.S. Geological Survey research
published today in Geophysical Research Letters.
Since late
2009 the rate of magnitude 3 or larger earthquakes in north-central Oklahoma
has been nearly 300 times higher than in previous decades. More than 3,600
earthquakes between 2009 and 2014 were located and determined to occur on
near-vertical, strike-slip faults at a shallow depth of 4 to 6 kilometers.
Several of these earthquakes caused damage and many were felt, with over
153,000 individual felt reports for 474 separate earthquakes entered at the
USGS
“By
identifying the faults, we are providing some guidance about where major
earthquakes can happen,” said Dan McNamara, USGS research geophysicist and lead
author of the new paper.
These
reactivated structures were originally formed approximately 300 million years
ago and are well known as structural traps in oil and gas bearing geologic
formations. A primary reason for reactivation is the northeast or northwest
orientation of the faults relative to the east to west direction of regional
tectonic stress in earth’s upper crust, which increases the probability of a
future, larger earthquake.
Several
recent studies have linked Oklahoma earthquakes with the injection of
wastewater from enhanced oil and gas exploration. The purpose of this new study
is to inform engineers, the insurance industry and government agencies about
the increased earthquake risk in the state, and not to link earthquakes in
Oklahoma to oil and gas extraction. These findings will be used to develop a
new earthquake-hazard map for Oklahoma that the USGS is planning to issue later
this year, which will mark the first time the state’s earthquake hazard maps
will include suspected human-induced earthquakes.
Current
hazard maps, which show the likelihood of an area experiencing earthquake
shaking of various intensities, do not include induced seismicity and could be
underestimating the earthquake hazard for Oklahoma and other states, McNamara
explained. Augmenting these maps with information about the type, length and
location, of the reactivated faults will help officials provide guidance to the
oil and gas industry and aid in adapting building codes to ensure that
structures can withstand more damaging earthquakes, he added.
The research
was conducted in cooperation with the Oklahoma Geological Survey.
SOURCE: http://www.usgs.gov
Released:
3/6/2015 12:31:58 PM
Contact
Information:
U.S.
Department of the Interior, U.S. Geological Survey
Office of
Communications and Publishing
12201
Sunrise Valley Dr, MS 119
Reston, VA
20192 Heidi Koontz 1-click interview
Phone:
303-202-4763
