OKLAHOMA CITY (AP) — A strong, 4.3-magnitude earthquake woke many people in the Oklahoma City area early Tuesday and knocked out power to thousands of homes, the latest in a series of temblors that's prompted state regulators to call for more restrictions on oil and gas operators.
The quake struck at 5:39 a.m. near Edmond, a suburb north of Oklahoma City, according to preliminary data from the U.S. Geological Survey. A smaller earthquake with a preliminary magnitude of 3.4 hit the same area about 10 minutes later.
No injuries were immediately reported, but the quake knocked out power to about 4,400 homes and businesses; electricity was restored quickly, Edmond spokesman Casey Moore said. Edmond police received about 15 reports of alarms going off at homes and businesses in the minutes after the quake.
Moore, who lives a little more than a mile from the epicenter, said the temblor woke his entire family.
"We had some things that fell off the shelves and walls ... picture frames, a platter that fell off a shelf and broke," Moore said.
Oklahoma has become one of the most earthquake-prone areas in the world, with the number of quakes magnitude 3.0 or greater skyrocketing from a few dozen in 2012 to more than 800 so far this year. Many of the earthquakes are occurring in swarms in areas where injection wells pump salty wastewater — a byproduct of oil and gas production — deep into the earth. As a result, state regulators have begun reducing the volume or shutting down disposal wells in response.
State Rep. Richard Morrissette, an Oklahoma City Democrat, on Tuesday called for more to be done, asking for a complete halt of any wastewater being injected into the underground Arbuckle formation in counties where seismic activity has increased.
The epicenter of Tuesday's quake was located just outside a previously implemented "cutback zone," where disposal well operators were directed in July to reduce the amount of volume they inject, Oklahoma Corporation Commission spokesman Matt Skinner said. He added that there were no high-volume injection wells operating in the area of Tuesday's quake.
"The classic suspects, according to researchers, are injection wells that are both deep and high volume, and we don't have any wells that meet that description," Skinner said.
While most well operators follow the commission's instructions, Oklahoma City-based Sandridge Energy Inc. has refused to cut back volume or comply with the agency's directive. Skinner said the agency's oil and gas division is asking the commission to order the company to comply in an application that will be presented early next month.
Sandridge spokesman David Kimmel has said the company wants to ensure the commission's decisions "are based on scientific analysis."
The strongest earthquake on record in Oklahoma is a magnitude 5.6 centered in Prague in November 2011 that damaged 200 buildings and shook a college football stadium.
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