Killer tornadoes, sizzling summers, treacherous ice storms. Barbara Scott was prepared for all that and more when she moved from Denver to Bluff City, Kan., a half dozen years ago. But earthquakes? In Kansas?
"It's like the earth just rolled under my house, raised it up and lowered it down," she said of the quake that struck last month between Bluff City and Caldwell. Further rattling Scott was the possibility that the earthquake was man-made, a byproduct of our lust for energy.
"We thought it might be the fracking," she said. "We have so much of that going on down here."
Kansas is one of five states least likely to experience earthquake damage, state officials say. The worst on record was of 5.5 magnitude in 1867 near Manhattan.
Then last fall, a swarm of tremors shook south-central Kansas sporadically over a couple of months. The culmination was a 3.8-magnitude quake on Dec. 16 that rattled windows, cracked walls and shook furniture in Sumner and Harper counties along the Kansas-Oklahoma border.
There were no injuries or reports of major damage. But the December temblor and the smaller ones leading up to it startled flatlanders unaccustomed to the kind of tremors Californians might shrug off. "It shook the house and rattled the windows," Bluff City resident Chris Garancosky said of the first quake she felt, on Sept. 9. "I thought somebody's propane tank had blown up."
Was it a fluke of nature, the earth shaking off pent-up tectonic pressure that had been building over centuries? Or might it have been yet more evidence of a phenomenon that scientists believe is on the rise throughout the nation's midsection?
That would be earthquakes with links to hydraulic fracking, the process of flushing hard-to-get oil and gas from porous, underground rock formations by fracturing them with a high-pressure mixture of water, chemicals and sand.
Fracking itself is not thought to cause quakes that people can feel. But scientists and the energy industry do agree that seismic activity can be induced when millions of gallons of wastewater from hydraulic fracturing operations are injected into the kind of disposal wells that are being used by oil and gas companies in the Bluff City area.
"I think the sense at this point," said Rex Buchanan, acting director of the Kansas Geological Survey, "is there's a reasonable chance that (the Dec. 16 temblor) was an induced earthquake."
Buchanan's agency and the Kansas Corporation Commission have yet to determine what caused the Dec. 16 quake.
One part of their investigation will be to learn how much wastewater was injected into the disposal wells nearest the quake's epicenter. Four companies have wells in that area, commission spokesman Jesse Borjon said.
Scientists have long known that injecting fluids deep into the earth can trigger earthquakes.
"There's really no doubt in the credible scientific community about that connection," said Joe Spease, chairman of the hydraulic fracturing committee at the Kansas Sierra Club.
But it's difficult to prove that a specific quake was caused by injecting fluid into a specific well, and overall the risks of damage by earthquakes are low, according to independent experts and the energy industry.
"Only a small fraction of the thousands of injection wells that exist have been tied to seismic events of notice to the public," said Dana Bohan at Energy in Depth, the research arm of the Independent Petroleum Association of America.
Still, scientists at the U.S. Geological Survey think that the frequency of earthquakes increases when wastewater floods fault zones, causing pieces of Earth's fractured crust to slip more often than they might otherwise.
The USGS points to a steep increase in the number of earthquakes in the last few years in regions of the country where oil and gas production through fracking has ramped up.
From 2010 to 2012, there were more than 300 earthquakes with a magnitude of 3 or above in the central and eastern United States. Compare that with 21 per year on average from 1967 to 2000, after which the number began to creep up.
Many of those recent quakes have occurred in Oklahoma, where a fracking boom is underway. The most powerful was a 5.6-magnitude quake centered near Prague, Okla., on Nov. 5, 2011, that destroyed 14 homes, injured two people and was felt in Kansas City and in parts of at least 17 states.
A study published in March in the journal Geology suggested that the Prague quake was possibly caused by the injection of wastewater into wells that are a mile or two deep. That same month, the Oklahoma Geologic Survey attributed the quake to "natural causes."
In Kansas, where 5,000 similar wells are scattered across the state, the debate is only now beginning to rumble.
Over the last several years, millions of gallons of salty, toxic waste material, some of it with low levels of radioactivity, have been disposed of in those wells, which bottom out far below the water table.
The oil and gas industry's use of disposal wells has been on the rise in the last couple of years because until recently it seemed as if the state's oil and gas industry might be on the cusp of a revival, thanks to fracking.
"Kansas is going to be a major player in this," Gov. Sam Brownback told a crowd of hundreds who came to hear about the pending oil and gas boom in the fall of 2012.
But to the chagrin of industry and state officials who had counted on the tax revenue, Kansas hasn't turned out to be the next North Dakota, where the economy has spiked since fracking began.
The cost of extracting gas from Kansas' underground rock formations often outweighs the returns. In the past year, some companies have cut back or stopped further exploration.
"What I told the governor and the Legislature back then is don't let the hype overwhelm the hope," said Ed Cross, president of the Kansas Independent Oil & Gas Association.
Neither has fracking led to a spike in statewide oil production, which increased a modest 6.6 percent last year, Cross said. However, a few counties along the Oklahoma border have done well. Among the beneficiaries is Harper County, near the epicenter of last month's quake.
"There's a lot of production, a lot of drilling going on," said Harper County economic development director Mike Lanie. "These wells are coming in so strong and big."
After nearly two decades in which oil production rarely topped 350,000 barrels a year, oil companies pulled 873,000 barrels out of the Mississippian lime formation beneath Harper County in 2012.
Production increased to nearly 1.2 million barrels in the first nine months of 2013, with final annual figures to come.
At least one oil company has quit adding wells in the county, but other producers are bullish, Lanie said. Oil tax revenues are in the millions in a county with 6,000 people.
Some 300 apartments have been added to the housing stock, there are two new hotels and the jobless rate at 3 percent is less than half the national average.
"Overall, it's been very good for our community," Lanie said. But then there are the tremors. If not fearful, some people are at least somewhat concerned about the future.
"Everybody wants to know if this fracking is causing the earthquakes," said Gwen Warner, chamber of commerce executive director in Anthony, the Harper County seat.
The Dec. 16 quake caused little damage, at least that anyone can verify. Garancosky said she now has cracks in her walls, but it's possible some of them were there before.
But Warner and others have been checking to see what it might take to add earthquake coverage to their homeowner policies. "One agent in the area told me that prior to the earthquake, her office had hardly received any earthquake inquiries, but since then she has added half a dozen endorsements," State Farm Insurance spokesman Jim Camoriano said.
In Oklahoma, which now experiences about 40 quakes annually, the state's insurance commissioner recently encouraged residents to buy earthquake insurance. It runs $100 to $150 a year.
The cost depends on the value of the property, whether the house is made of wood or brick (wood withstands a quake better) and how far it is from a known fault line, Camoriano said.
(c)2014 The Kansas City Star