The state’s ongoing, three-year earthquake swarm has produced thousands of tiny earthquakes, but just 20 magnitude 4.0 or greater and only one magnitude 5.0 or greater.
One of the most pressing questions is whether another big one — or something even stronger — is likely.
As with so many other issues, the answer is unclear and depends on who you ask.
One earthquake theory is that every time the earth releases a minor quake, the risk of a larger shaker is reduced or delayed.
Priyank Jaiswal, assistant professor of seismology at Oklahoma State University’s Boone Pickens School of Geology, said the theory is similar to the one used to minimize the risk of wildfires.
“The reason you have controlled wildfires is so if it burns in bits and pieces, a natural fire is not as bad,” Jaiswal said. “With earthquakes, if you have many, many small earthquakes, there is a chance that it could delay the occurrence of a big natural earthquake because the sediments or rocks are adjusting themselves.”
The other thought is that the smaller slips could actually cause new pressure and that like pulling back on a rubber band, eventually it will cause a larger quake.
“There are two sides here,” Jaiswal said. “I don’t know which is right. Nobody can say.”
Cliff Frohlich, senior research scientist at the University of Texas’ Institute for Geophysics, agreed it is difficult to know whether the state is at risk for a bigger quake.
“One problem with earthquake prediction is we’re not very good at it,” he said. “There are plenty of times you have 2’s and 3’s and that’s all. Most of the time that’s what happens.”
The smaller quakes have caused minimal damage.
“I look at earthquakes like storms,” Frohlich said. “When you get a little storm, the next day, people are talking about the amount of rain and hail. They’re having fun with it. But if you have a hurricane with 200 mph winds, it’s not fun. A magnitude 3 is fun. You talk to people the next day and ask if they felt it. But a magnitude 7 is not fun.”
Besides the risk of a larger quake, Oklahomans also face the risk of cumulative damage from the thousands of smaller quakes it already has experienced. On their own, most of the smaller quakes go unnoticed and cause little or no damage.
But some have questioned whether the combined effect of thousands of smaller quakes can cause damage to pipelines, bridges or other infrastructure.
“It probably does, but they (small quakes) are more of a nuisance,” retired U.S. Geological Survey researcher David Gordon said. “It doesn’t add up to structural damage to well-built buildings. But if you have an old building with cracking walls or plaster, it could add up cumulatively.”
One problem with earthquake prediction is we’re not very good at it. There are plenty of times you have 2’s and 3’s and that’s all. Most of the time that’s what happens.”Senior research scientist at the University of Texas’ Institute for Geophysics