Wichita to be looking for quake damage this week

Saturday’s earthquake did more than scare people.

This one was stronger than the quakes that shook us before. And it did more than rattle dishes and bang bookcases against walls.

The force of the magnitude-5.6 earthquake was jarring enough that Wichita city staff members and state inspectors in Oklahoma immediately fanned out to look for damage. They’ll spend the next few days taking a long look at bridges, sewage facilities and buildings.

The record-tying quake, which shook Wichitans and other Midwesterners from Nebraska to north Texas, could bring fresh attention to the practice of disposing oil and gas field wastewater deep underground.

On Saturday afternoon, state officials in Oklahoma directed about 35 wastewater disposal wells within an approximate 500-square-mile radius of the quake’s epicenter to shut down within seven to 10 days.

The quake, which struck at 7:02 a.m. on Saturday, matched a November 2011 quake for Oklahoma’s strongest on record. The U.S. Geological Survey recorded subsequent earthquakes of magnitudes 3.6, 3.4 and 2.9.

“I heard a deep, unnatural rumble, like a large truck going by,” said Jennifer Fry, a college adviser and retired teacher in Wichita.

“Everything in the house was rattling,” said David Welfelt. His home on the south edge of Newton rattled for at least 45 seconds. “The bookshelves in my wife’s office were banging the walls.”

Sedgwick County emergency dispatchers received 66 calls from people dialing 911.

“People were shook up,” a dispatcher said. “Some of them thought maybe the noise was someone breaking in.”

Three buildings sustained moderate damage in Pawnee, Okla., a town of 2,200 about 9 miles southeast of the epicenter. Several others had minor damage.

“We’ve got buildings cracked,” said Mark Randell, the Pawnee County Emergency Management director. There also were reports of extensive damage in rural houses near the epicenter, which was about 21 miles southeast of Ponca City, Okla.

A man suffered a minor head injury when part of a fireplace fell on him, Randell said. The man was treated and released.

Staff members from Wichita’s public works department have found minor damage in city buildings so far, said Van Williams, a city spokesman. Inspections will continue into next week.

Library staff members at the city’s central branch found minor cracks in a wall and window, said Cynthia Berner, director of libraries.

The damage is not as severe as that caused by the 2011 quake near Prague, Okla., about 60 miles south of Pawnee, even though they were the same magnitude and approximately the same depth below the surface. Saturday’s quake was 3.7 miles deep, compared to 3.1 miles in 2011.

Hard bedrock beneath the ground’s surface in north-central Oklahoma is likely the reason for less damage, said Jefferson Chang, a physicist with the Oklahoma Geological Survey, adding that the subsurface around Prague is softer.

“In harder rock, it won’t shake as much,” he said.

Wichitans’ reactions

Wichitans who felt the quake lit up social media and sent a number of comments to The Eagle.

“It sounded like rain hitting the house,” said Sherry Chapman, a teacher at Wichita State University who lives south of Wichita. “It was the sound of all our dishes rattling in the china cupboard in the dining room, I think.”

“Felt it on the fourth floor of St. Francis hospital,” said Susan Howell, a Wichitan who was visiting a patient there. “Bed shook like a vibrator had been turned on, but the IV bags were swaying, too. Whew.”

Sheri Talbot lives in southwest Wichita: “I was outside, and it felt like someone was shaking my chair,” she said. “Then all my fence decorations started rattling. It felt like it lasted two minutes.”

Some people slept through it.

“Woke up my 4th grader, who announced that it made her feel ‘dizzy,’ ” said Marc Bennett, Sedgwick County district attorney. On the other hand, Bennett said, “The 8th grader could sleep through a John Phillips Souza (sic) brass band in her room.”

Besides those in the Wichita area, people in Kansas City; St. Louis; Fayetteville, Ark.; Des Moines; Dallas; and Lincoln, Neb., all reported feeling the earthquake and hearing parts of their houses rattle hundreds of miles from the epicenter.

“We’re visiting friends in Fort Smith, Arkansas, and felt it here,” said Mike Hill, a retired Sedgwick County sheriff.

“I ran out into the hall and noticed light fixtures swaying,” said Colleen Fleischer, a former Wichitan living in Lincoln.

She said Nebraskans were saying on social media that the seismic disturbance was the Husker Nation waking up. The University of Nebraska’s football team was scheduled to play Fresno State on Saturday in Lincoln.

Wastewater disposal link

An increase in the number of earthquakes of magnitude 3.0 or greater in Oklahoma has been linked to underground disposal of wastewater from oil and natural gas production.

The U.S. Geological Survey acknowledged in a statement that oil and gas activity has set off many earthquakes in the states but said it could not yet say the practice caused Saturday’s quake.

The area where the quake was centered is on the edge of a region covered by a “regional earthquake response plan” issued in March by the Oklahoma Corporation Commission, whose goal was to cut the number of earthquakes by reducing wastewater injection volume by 40 percent from 2014 levels.

Oklahoma and Kansas both had an uptick in quakes in the first half of this decade. Kansas moved quickly to limit wastewater volume, while Oklahoma concentrated on the depth of the disposal. Kansas saw a 60 percent drop in the number of quakes, while the frequency of quakes in Oklahoma continued to climb.

Some parts of Oklahoma now match northern California for the nation’s most shake-prone regions, and one area in Oklahoma has a 1 in 8 chance of a damaging quake in 2016, with other parts closer to 1 in 20.

The corporation commission said Saturday it would take some time to shut down wells in the area of the quake.

“All of our actions have been based on the link that researchers have drawn between the Arbuckle disposal well operations and earthquakes in Oklahoma,” spokesman Matt Skinner said Saturday. “We’re trying to do this as quickly as possible, but we have to follow the recommendations of the seismologists, who tell us everything going off at once can cause an (earthquake).”

This story was originally published September 3, 2016 at 9:01 AM with the headline "Wichita to be looking for quake damage this week."