2011 Oklahoma Induced Earthquake May Have Triggered Larger Quake plus 1 more

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Title: USGS Newsroom

2011 Oklahoma Induced Earthquake May Have Triggered Larger Quake plus 1 more

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2011 Oklahoma Induced Earthquake May Have Triggered Larger Quake

Posted: 06 Mar 2014 01:00 PM PST

Contact Information:

Susan  Garcia ( Phone: 650-346-0998 );

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PASADENA, Calif. — In a new study involving researchers at the U.S. Geological Survey, scientists observed that a human-induced magnitude 5.0 earthquake near Prague, Oklahoma in November 2011 may have triggered the larger M5.7 earthquake less than a day later. This research suggests that the M5.7 quake was the largest human-caused earthquake associated with wastewater injection.

"The observation that a human-induced earthquake can trigger a cascade of earthquakes, including a larger one, has important implications for reducing the seismic risk from wastewater injection," said USGS seismologist and coauthor of the study Elizabeth Cochran.

Historically, earthquakes in the central United States have been uncommon. Yet in the year 2011 alone, numerous moderate-size earthquakes occurred in Colorado, Texas, Oklahoma, Ohio and Arkansas.  Many of these earthquakes occurred near waste-water injection wells, and some have been shown to be caused by human activities.

The 2011 Oklahoma earthquake sequence included the November 6, 2011, M5.7 earthquake that ruptured a part of the Wilzetta fault system, a complex fault zone about 200 km (124 mi) in length near Prague, Oklahoma.  Less than 24 hours prior to the M5.7 earthquake, a M5.0 foreshock occurred on November 5, 2011.  That foreshock occurred near active waste-water disposal wells, and was linked in a previously published study to fluid injection in those wells.  The earthquakes have not been directly linked to hydrofracturing. 

The research published this week suggests that the foreshock, by increasing stresses where M5.7 mainshock ruptured, may have triggered the mainshock, which in turn, triggered thousands of aftershocks along the Wilzetta fault system, including a M5.0 aftershock on November 8, 2011. If this hypothesis is correct, the M5.7 earthquake would be the largest and most powerful earthquake ever associated with wastewater injection.  All three earthquakes of magnitude 5.0 and greater along the Wilzetta fault exhibited strike-slip motion at three independent locations along the fault, suggesting that three separate portions of the Wilzetta fault system were activated.  

The paper, "Observations of Static Coulomb Stress Triggering of the November 2011 M5.7 Oklahoma Earthquake Sequence," by D.F. Sumy, E.S. Cochran, K.M. Keranen, M. Wei, G.A. Abers, from the University of Southern California, USGS, University of Oklahoma, Brown University, and the Lamont Doherty Earth Observatory at Columbia University, was published in the "Journal of Geophysical Research" this week.

Global Undiscovered Copper Resources Estimated at 3.5 Billion Metric Tons

Posted: 06 Mar 2014 07:30 AM PST

Contact Information:

Diane Noserale ( Phone: 703-648-4333 ); Larry Meinert ( Phone: 703-648-6100 );

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The first-ever, geologically-based global assessment of undiscovered copper resources estimates that 3.5 billion metric tons of copper may exist worldwide. The U.S. Geological Survey outlined 225 areas for undiscovered copper in 11 regions of the world.  The amount of undiscovered global copper estimated by the USGS would be enough to satisfy current world demand for more than 150 years.

According to the assessment, South America is the dominant source for both identified and undiscovered copper resources.  Particularly important, several regions of Asia including China have a large potential for undiscovered copper resources.

"This ground-breaking USGS assessment of future copper resources identifies a huge potential supply that is roughly six times greater than all the copper mined throughout human history," said Interior Assistant Secretary for Water and Science, Anne Castle. "If enough of this copper can be developed in an environmentally responsible and economical way, it will be a boon to new manufacturing and other initiatives that rely on the availability of copper such as the Administration's energy efficiency initiative."

Copper is one of the first metals ever extracted and its first use in coins dates back to about 8000 B.C. It continues to be the material of choice for a variety of industrial needs.

"Copper is one of the building blocks of civilization and is used in almost every aspect of modern life such as plumbing, electrical wiring, cars, cell phones, and energy systems such as wind turbines. In fact, copper has become so valuable that it is even being stolen from construction sites and out of backyards," said Larry Meinert, USGS Mineral Resources Program Coordinator. 

U.S. consumption is 2 million metric tons of copper per year whereas world consumption is about 20 million metric tons per year. 

The USGS Global Copper Assessment was completed in cooperation with numerous international collaborators from national geological surveys, industry, and academia. The USGS is the principal Federal provider of research and information on nonfuel mineral resources.  

Supporting studies, including documentation of the assessment methodology, descriptions of individual tracts, and spatial data for use in geographic information systems (GIS) are available from the USGS Mineral Resources Program.  Information on production and consumption of copper as well as general information about copper is available from the USGS.

Global copper consumption. (High resolution image)