10 aftershocks follow 5.6 Earthquake in Oklahoma

[Pastor Dale Morgan]

Great Earthquakes In Diverse Places

10 aftershocks follow 5.6 Earthquake in Oklahoma


SPARKS, Okla. (AP) – Oklahoma residents more accustomed to tornadoes than earthquakes have been shaken by weekend temblors that cracked buildings, buckled a highway and rattled nerves. One quake late Saturday was the state's strongest ever and jolted a college football stadium 50 miles away.


Many homes and other buildings cracked and suffered minor damage, there were no reports of severe injuries.

Saturday night's earthquake jolted Oklahoma State University's stadium shortly after the No. 3 Cowboys defeated No. 17 Kansas State.

"That shook up the place, had a lot of people nervous," Oklahoma State wide receiver Justin Blackmon said. "Yeah, it was pretty strong."

The magnitude-5.6 earthquake late Saturday was Oklahoma's strongest on record, said Jessica Turner, a geophysicist with the U.S. Geological Survey. Centered near Sparks, 44 miles northeast of Oklahoma City, it could be felt throughout the state and in Arkansas, Kansas, Missouri, northern Texas and some parts of Illinois and Wisconsin. It followed a magnitude-4.7 quake early Saturday that was felt from Texas to Missouri.

The weekend earthquakes were among the strongest yet in a state that has seen a dramatic, unexplained increase in seismic activity. Oklahoma typically had about 50 earthquakes a year until 2009. Then the number spiked, and 1,047 quakes shook the state last year, prompting researchers to install seismographs in the area. Still, most of the earthquakes have been small.

Geologists now believe a magnitude-4.7 earthquake Saturday morning was a foreshock to the bigger one that followed that night. They recorded 10 aftershocks by midmorning Sunday and expected more. Two of the aftershocks, at 4 a.m. and 9 a.m., were big, magnitude-4.0.

"We will definitely continue to see aftershocks, as we've already seen aftershocks from this one," said Paul Earle, a seismologist with the USGS in Golden, Colorado. "We will see aftershocks in the days and weeks to come, possibly even months."

Several homeowners and businesses reported cracked walls, fallen knickknacks and other minor damage. Brad Collins, the spokesman for St. Gregory's University in Shawnee, said one of the four towers on its "castle-looking" administration building had collapsed and the other three towers were damaged. He estimated the towers were about 25 feet tall.

In Sparks, Joe Reneau said clouds of dust belched from the corners of almost every room in his house and a roar that sounded like a jumbo jet filled the air. Reneau's red-brick chimney collapsed and fell into the roof above the living room. By the time the shaking stopped, a pantry worth of food had been strewn across the kitchen and shards of glass and pottery covered the floor.

"It was like WHAM!" said Reneau, 75, gesturing with swipes of his arms. "I thought in my mind the house would stand, but then again, maybe not."

An emergency manager in Lincoln County near the epicenter said U.S. 62, a two-lane highway that meanders through rolling landscape between Oklahoma City and the Arkansas state line, crumpled in places when the stronger quake struck Saturday night.

The crowd of nearly 59,000 was still leaving Oklahoma State's Boone Pickens Stadium when the earthquake hit, and players were in the locker rooms beneath the stands. The shaking seemed to last the better part of a minute, rippling upward to the stadium press box.

"Everybody was looking around, and no one had any idea," Oklahoma State quarterback Brandon Weeden said. "We thought the people above us were doing something. I've never felt one, so that was a first."

A few hours before dawn Sunday, the latest quake set nerves on edge anew.

Jessie Plumb, a registered nurse at Prague Community Hospital, said she and other staffers felt the magnitude-4.0 quake while on the second floor of the building.

"It kind of gave a little bit of a shake, a little bit of rock 'n roll," she said by telephone. "I would say it was 20 or 25 seconds."

Oklahoma has had big earthquakes before. USGS records show a magnitude-5.5 earthquake struck El Reno, just west of Oklahoma City, in 1952.

Turner said an active spate of earthquakes started in the region in February 2010 and the latest activity appears to be part of that trend. But experts are still puzzling out why the latest quakes have been concentrated in such a small geographic area around Sparks, she said.

Scientists say they have no explanation for the quakes. They happened along an ancient fault, although it's not clear yet whether shifting along the fault is what caused them, Earle said. One reason earthquakes are hard to predict in Oklahoma is that the state sits over a series of smaller ancient faults, rather than a major fault, such as California's San Andreas Fault, he said.

Arkansas also has seen a big increase in earthquake activity, which residents have blamed on injection wells. Natural gas companies engaged in hydraulic fracturing, or fracking, use fluid to break apart shale and rock to release natural gas. Injection wells then dispose of the fluid by injecting it back into the ground.

There are 181 injection wells in the Oklahoma county where most of the weekend earthquakes happened, said Matt Skinner, spokesman for the Oklahoma Corporation Commission, which oversees oil and gas production in the state and intrastate transportation pipelines.

But natural gas companies claim there is no proof of a connection between injection wells and earthquakes, and a study released earlier this year by an Oklahoma Geological Survey seismologist seems to back that up. It found most of the state's seismic activity didn't appear to be tied to the wells, although more investigation was needed. The state survey didn't respond to phone messages left Sunday.

Earle said he couldn't comment on the relationship between fracking, injection wells and earthquakes.