Tag Archives: William Ellsworth of the U.S. Geological Survey

Quake experts think fracking maps may predict future temblors

Repost from the San Antonio Express-News 

Quake experts think fracking maps may predict future temblors

Experts creating models to gauge future activity

By Sean Cockerham, Tribune News Service Washington Bureau, April 23, 2015 10:02pm
Chad Devereaux works to clear up bricks that fell from three sides of his in-laws' home in Sparks, Okla, after two earthquakes hit the area in less than 24 hours in 2011. A government report released Thursday found that a dozen areas in the United States have been shaken in recent years by small earthquakes triggered by oil and gas drilling, Photo: Associated Press File Photo / AP
Chad Devereaux works to clear up bricks that fell from three sides of his in-laws’ home in Sparks, Okla, after two earthquakes hit the area in less than 24 hours in 2011. A government report released Thursday found that a dozen areas in the United States have been shaken in recent years by small earthquakes triggered by oil and gas drilling, Photo: Associated Press File Photo / AP

WASHINGTON — As earthquakes triggered by oil and gas operations shake the heartland, the federal government is scrambling to predict how strong the quakes will get and where they’ll strike.

The U.S. Geological Survey released maps Thursday that show 17 areas in eight states with increased rates of manmade earthquakes, including places such as North Texas, southern Kansas and Oklahoma where earthquakes were rare before fracking sparked a U.S. drilling boom in recent years.

Seismologists are using the maps in an attempt to create models that can predict the future of such quakes.

“These earthquakes are occurring at a higher rate than ever before and pose a much greater risk to people living nearby,” said Mark Petersen, chief of the USGS national seismic hazard modeling project.

Studies show the earthquakes primarily are caused by the injection of drilling wastewater from oil and gas operations into disposal wells, said Bill Ellsworth, a seismologist with the USGS.

The fact there have been many small earthquakes “raises the likelihood of larger earthquakes,” Ellsworth said. While most of the quakes have been modest, a 5.7-magnitude earthquake near Prague, Oklahoma, in 2011 destroyed 14 homes and was felt as far away as Milwaukee.

The USGS is working on a model, to be released at the end of the year, that can predict the hazards a year in advance.

People who live in areas with manmade quakes can use the forecasting information to upgrade structures to be safer and in order to learn what they should do in case of an earthquake, he said.

“Many of these earthquakes are now occurring in areas where people have not been familiar with earthquakes in the past,” Ellsworth said. “So there’s just a lot of basic education that is worth doing.”

The USGS maps show the earthquakes are mostly in Oklahoma, Texas and Kansas, but also Colorado, Ohio, Arkansas, Alabama and New Mexico.

“What we’ve seen is very, very large volumes of wastewater being injected over many different areas in the midcontinent, Oklahoma principally but also Kansas, Texas and other states,” Ellsworth said.

Fracking produces large amounts of wastewater, which oil and gas companies often pump deep underground as an economical way to dispose of it without contaminating fresh water. That raises the pressure underground and can effectively lubricate fault lines, weakening them and causing earthquakes.

While there was some initial skepticism, it’s become increasingly accepted that oil and gas activities are behind the surge in American earthquakes since 2008. Southern Methodist University researchers said in a research paper this week that these activities were the most likely cause of a rash of earthquakes that hit an area northwest of Fort Worth, Texas, from November 2013 to January 2014.

Oklahoma was rocked with nearly 600 earthquakes big enough for people to easily feel last year.

The Kansas Corporation Commission, a state regulatory agency, has responded to the earthquakes there with new rules that limit how much saltwater drilling waste can be injected underground. Ellsworth said seismic researchers were watching Kansas closely to see whether the new rules reduced the quakes.

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    Federal study: Oklahoma more at risk of big damaging quakes because of increase in small ones

    Repost from The Vallejo Times-Herald (Covered elsewhere, including U.S. News and World Report)

    Federal study: Oklahoma more at risk of big damaging quakes because of increase in small ones

    By Seth Borenstein, AP Science Writer, Feb 14, 2015
    File - In this Nov. 6, 2011 file photo, maintenance workers inspect the damage to one of the spires on Benedictine Hall at St. Gregory's University in Shawnee, Okla., after two earthquakes hit the area in less than 24 hours. New federal research says small earthquakes shaking Oklahoma and southern Kansas daily are dramatically increasing the chance of bigger and dangerous quakes, new federal research indicates. (AP Photo/Sue Ogrocki)
    Maintenance workers inspect the damage to one of the spires on Benedictine Hall at St. Gregory’s University in Shawnee, Okla., after two earthquakes hit the area in less than 24 hours. New federal research says small earthquakes shaking Oklahoma and southern Kansas daily are dramatically increasing the chance of bigger and dangerous quakes. Associated Press/Nov. 6, 2011

    SAN JOSE, California (AP) — Small earthquakes shaking Oklahoma and southern Kansas daily and linked to energy drilling are dramatically increasing the chance of bigger and dangerous quakes, federal research indicates. This once stable region is now just as likely to see serious damaging and potentially harmful earthquakes as the highest risk places east of the Rockies such as New Madrid, Missouri, and Charleston, South Carolina, which had major quakes in the past two centuries. Still it’s a low risk, about a 1 in 2,500 years’ chance of happening, according to geophysicist William Ellsworth of the U.S. Geological Survey. “To some degree we’ve dodged a bullet in Oklahoma,” Ellsworth said after a presentation to the American Association for the Advancement of Science. But, he added, “This is not to say we expect a large earthquake tomorrow.” During the 90-minute session on human-induced earthquakes, three quakes larger than 3.1 magnitude hit northern Oklahoma. Federal records show that since Jan. 1, Oklahoma has had nearly 200 quakes that people have felt. These quakes started to increase in 2008 and made dramatic jumps in frequency in June 2013 and again in February 2014, Ellsworth said. They are mostly in areas with energy drilling, often hydraulic fracturing, a process known as fracking. Many studies have linked the increase in small quakes to the process of injecting wastewater deep underground because it changes pressure and triggers dormant faults. Until now, those quakes were mostly thought of as nuisances and not really threats. But Ellsworth’s continuing study, which is not yet published, showed the mere increase in the number of tiny temblors raises the risk of earthquakes that scientists consider major hazards. That’s generally above a magnitude 5 with older buildings and a magnitude 6 for modern ones, Ellsworth said. “The more small earthquakes we have it just simply increases the odds we’re going to have a more damaging event,” Ellsworth said. A 2011 earthquake in Prague, Oklahoma, was a 5.7 magnitude, causing some damage and hurting two people. Some studies said that was a side effect of the drilling process, but other scientists are not convinced. Experts at the science session said Ellsworth’s finding of a higher risk for big quakes makes sense. “We are worried about this, no question about it,” said Rex Buchanan, interim director of the Kansas Geological Survey. Not all states with fracking and wastewater injections are seeing increased quakes and not all those with increased quakes, such as Texas and Ohio, are at a higher risk for major quakes, Ellsworth said. Arkansas and Ohio, for example, are also now seeing fewer man-made quakes, he said. Much depends on geology and how the wastewater is injected, said Stanford University geophysics professor Mark Zoback. He said industry and regulators can be smarter about where they inject wastewater and where they do not, and can avoid many of these problems.

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