The Enid News and Eagle, Enid, OK

National and world

April 6, 2012

Study ties oil, gas production to Midwest quakes

NEW YORK — Oil and gas production may explain a sharp increase in small earthquakes in the nation's midsection, a new study from the U.S. Geological Survey suggests.

The rate has jumped six-fold from the late 20th century through last year, the team reports, and the changes are "almost certainly man-made."

Outside experts were split in their opinions about the report, which is not yet published but is due to be presented at a meeting later this month.

The study said a relatively mild increase starting in 2001 comes from increased quake activity in a methane production area along the state line between Colorado and New Mexico. The increase began about the time that methane production began there, so there's a "clear possibility" of a link, says lead author William Ellsworth of the USGS.

The increase over the nation's midsection has gotten steeper since 2009, due to more quakes in a variety of oil and gas production areas, including some in Arkansas and Oklahoma, the researchers say.

Latest earthquakes in the U.S.A.

 

It's not clear how the earthquake rates might be related to oil and gas production, the study authors said. They note that others have linked earthquakes to injecting huge amounts of leftover wastewater deep into the earth.

There has been concern about potential earthquakes from a smaller-scale injection of fluids during a process known as hydraulic fracturing, or fracking, which is used to recover gas. But Ellsworth said Friday he is confident that fracking is not responsible for the earthquake trends his study found, based on prior studies.

The study covers a swath of the United States that lies roughly west of Ohio and east of Utah. It counted earthquakes of magnitude 3 and above.

Magnitude 3 quakes are mild, and may be felt by only a few people in the upper floors of buildings, or may cause parked cars to rock slightly. The biggest counted in the study was a magnitude-5.6 quake that hit Oklahoma last Nov. 5, damaging dozens of homes. Experts said it was too strong to be linked to oil and gas production.

The researchers reported that from 1970 to 2000, the region they studied averaged about 21 quakes a year. That rose to about 29 a year for 2001 through 2008, they wrote, and the three following years produced totals of 50, 87 and 134, respectively.

The study results make sense and are likely due to man-made stress in the ground, said Rowena Lohman, a Cornell University geophysicist.

"The key thing to remember is magnitude 3s are really small," Lohman said. "We've seen this sort of behavior in the western United States for a long time."

Usually, it's with geothermal energy, dams or prospecting. With magnitude 4 quakes, a person standing on top of them would at most feel like a sharp jolt, but mostly don't last long enough to be a problem for buildings, she said.

The idea is to understand how the man-made activity triggers quakes, she said. One possibility is that the injected fluids change the friction and stickiness of minerals on fault lines. Another concept is that they change the below-surface pressure because the fluid is trapped and builds, and then "sets off something that's about ready to go anyway," Lohman said.

But another expert was not convinced of a link to oil and gas operations.

Austin Holland, the Oklahoma state seismologist, said the new work presents an "interesting hypothesis" but that the increase in earthquake rates could simply be the result of natural processes.

Holland said clusters of quakes can occur naturally, and that scientists do not yet fully understand the natural cycles of seismic activity in the central United States. Comprehensive earthquake records for the region go back only a few decades, he said, while natural cycles stretch for tens of thousands of years. So too little is known to rule out natural processes for causing the increase, he said.

___

Online:

Study abstract: http://bit.ly/HmqAxx

___

Science writer Seth Borenstein in Washington contributed to this report.

1
Text Only
National and world
  • Illinois Unemployment_Hass.jpg As U.S. job market strengthens, many don't feel it

    "If the economy is getting better, I'm not sure for whom. It certainly hasn't trickled down to me." — Douglas Hunter, who earned $14 an hour before the Great Recession and now works three days a week for $9.25 an hour, mopping floors and fixing fryers at McDonald's.

    July 31, 2014 1 Photo

  • House Obama Lawsuit.jpg Republican-led House approves lawsuit against President Obama

    Just a day before lawmakers were to begin a five-week summer recess, debate over the proposed lawsuit underscored the harshly partisan tone that has dominated the current Congress almost from its start in January 2013.

    July 31, 2014 1 Photo

  • Russia Putin web.jpg Sanctions could damage Russia

    The sanctions go further than earlier penalties — which had largely targeted individuals — by broadly limiting the trade of weapons and of technology that can be used in the oil and military industries. The EU also put its capital markets off-limits to Russian state-owned banks.

    July 31, 2014 1 Photo

  • Mideast Libya web.jpg Thousands flee to Tunisia to escape Libya fighting

    Many diplomats, including the U.S. ambassador, have pulled out of the country. With the interim government paralyzed, the fighting threatens the planned opening session of the newly elected parliament on Aug. 4.

    July 30, 2014 1 Photo

  • Obit Robert Drew web.jpg Cinema verite documentarian Robert Drew dies

    Starting in 1960 with “Primary,” Drew produced and sometimes directed a series of television documentaries that took advantage of such innovations as light hand-held cameras that recorded sound and pictures.

    July 30, 2014 1 Photo

  • Obama Ukraine Russia_Hass_W.jpg GOP-led House approves lawsuit against Obama

    The suit will contend that Obama has exceeded his constitutional powers in the way he has enforced the 2010 health care law.

    July 30, 2014 1 Photo

  • Texas: Gay-marriage ban best for children

    Texas’ ban on same-sex marriage allows the state to promote the birth and upbringing of children in “stable, lasting relationships,” the state’s attorney general argued Tuesday while asking a federal appeals court to reinstate the ban.

    July 30, 2014 1 Story

  • OKCupid, Facebook not alone in studying consumers

    Dating is hard.

    July 29, 2014

  • Abortion-Mississippi_Hass.jpg U.S. appeals court blocks Mississippi abortion law

    The 5th U.S. Circuit Court of Appeals voted 2-1 to overturn Mississippi’s 2012 law requiring abortion doctors to obtain admitting privileges at nearby hospitals.

    July 29, 2014 1 Photo

  • U.S. Court: Virginia marriage is for all lovers

    “We recognize that same-sex marriage makes some people deeply uncomfortable. However, inertia and apprehension are not legitimate bases for denying same-sex couples due process and equal protection of the laws,” Judge Henry F. Floyd wrote.

    July 28, 2014

Featured Ads