What's Causing the Earthquakes in Oklahoma?

Alaska and California have long reigned supreme as the earthquake capitals of the United States, but those two Pacific states are quickly being outrivaled.

And by Oklahoma of all places.

During the past few years the number of magnitude 3.0 or greater earthquakes in the Sooner State has increased by nearly 800 percent. In 2013, there were 106. In 2014, there were 585. Last year, Oklahoma officials counted 857, according to data cited by KOCO-TV.

To put the numbers into perspective, California records 15 to 20 quakes of magnitude 4.0 or greater each year, according to the U.S. Geological Survey. But in the first few weeks of 2016 alone, seismologists noted eight of them in Oklahoma.

So what’s causing these tremblers in a Great Plains state known more for its farmlands and ranches than its unstable earth? According to the Oklahoma Geological Survey, billions of barrels of wastewater being disposed of in deep underground caverns as a result of hydraulic fracturing, or fracking, a technique that uses water to recover gas and oil from shale rock. This wastewater apparently re-awakened old fault lines, according to NASA and geological experts.

Oklahoma state officials, including geological, utility, insurance and energy officials, are studying the problem and working to decrease the amount of wastewater injected into wells.

Fortunately, the earthquakes in Oklahoma have not caused widespread, devastating damage. But some experts predict the severity could worsen over time. If you live there, make sure your home and your family are ready for an earthquake.

Earthquake prep tips

Stock up on emergency supplies. The Red Cross has an emergency supply checklist for any kind of disaster, whether you’re at home or if you have to evacuate.

Identify places to take cover. Ready.gov recommends you “Drop, Cover, and Hold On!” to prevent injuries. Note places in your home where you’ll be safe from falling debris, such as under tables or desks. Then hold onto it and cover your eyes by putting your face in your arm. Teach kids to do the same. Don’t stand in a doorway for protection — that’s a myth. If you’re outside, move away from buildings, utility poles and wires, and drop to the ground.

Make an emergency plan with your family. If an earthquake happens while you’re all at work and school, discuss how you’ll find each other. Make sure everyone has an ICE (in case of emergency) number in their cellphone so emergency officials can contact your family if you are injured.

Consider earthquake insurance

Robert Hartwig, president and economist at the Insurance Information Institute, says many homeowners in Oklahoma are now opting for earthquake insurance. “These are minor earthquakes, for the most part,” he says. “What's happening is people are getting cracks here and there.”

Earthquake insurance, which is a separate policy from traditional homeowners insurance, usually carries deductibles of 2 to 10 percent on the total value of the home, Hartwig says. So if you own a $200,000 home, a 5 percent deductible means earthquake insurance would only cover damage over $10,000.

Be sure a policy doesn’t exclude damage that may be caused by wastewater disposal or hydraulic fracturing. One Oklahoma television station recently reported that of the 20 to 30 earthquake insurance options for residents, only four say in the policies they will cover damage caused by fracking.

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Ronald Agrella is a freelance writer and former editor of The Boston Globe’s Boston.com.