By SEAN MURPHY, Associated Press

OKLAHOMA CITY (AP) — At least seven earthquakes rattled north-central Oklahoma on Monday, including one felt 300 miles away in Iowa, prompting concern from local residents and policymakers that the state isn't doing enough to curb the quakes that scientists have linked to oil and gas activity.

Oklahoma has become one of the most earthquake-prone areas in the world, with the number of quakes magnitude 3.0 skyrocketing from a few dozen in 2012 to more than 720 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.

"It lasted for several seconds, but it's hard to tell when you just wake up," resident Frankie Robbins said of the 4.7 temblor that hit before 4 a.m. Monday some 16 miles from his home in Medford, which is about 80 miles south of Wichita, Kansas.

Robbins said the quakes left a few pictures askew on his wall, and he noticed a door frame in his house is "tighter than it used to be." And while no major damage or injuries were reported, Robbins said residents are growing increasingly uneasy about the frequency of the quakes.

"There's definitely a sense of concern for some people when they feel them in the middle of the night," Robbins said.

State regulators have taken steps to try and curb the number of quakes, working with disposal well operators in the area to have them reduce the volume in disposal wells or shut them down entirely. But so far the Oklahoma Corporation Commission's voluntary program has done little to curb the number of quakes.

State Rep. Cory Williams, a vocal critic of the state's response to the rise in seismic activity, praises the work done so far by the commission, but said overall the state's governor and Legislature has done little to address the problem since a state-record, 5.6-magnitude quake in 2011 that damaged 200 buildings and shook a college football stadium.

"The problem is we're being totally reactionary as opposed to proactive," said Williams, D-Stillwater. "We wait for a seismic event, and then we react to it, which is an abysmal policy for handling something that can cause catastrophic damage to property and/or life."

Williams said the powerful oil and gas lobby at the Capitol has kept lawmakers from taking any steps to regulate the industry. To make matters worse, he said, under a bill pushed by the industry that Gov. Mary Fallin signed into law last year, cities and towns would no longer be able to regulate oil and gas operations within their boundaries. A similar bill was signed into law in Texas.

"There's really just mass incompetence on the part of the Legislature not to do anything about this," Williams said. "They just don't seem to care."

But oil and gas industry officials say they're working with regulators to come up with a solution to the earthquake problem that doesn't jeopardize an industry that is critical to the state's economy.

"If you just shut it down, it would be devastating," said Chad Warmington, president of the Oklahoma Oil and Gas Association. "The goal is to be able to reduce earthquakes and still be able to produce."

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Oklahoma earthquakes: www.earthquakes.ok.gov

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