Transcript for Earthquakes Feared in Oklahoma
Now, to a rare earthquake advisory issued for Oklahoma. The first of its kind of any state east of the rockies. Experts say there's a good chance a big one could hit there. And Ryan Owens has the story. Reporter: Ominous warnings, the first of its kind for a state east of the rockies opinion it turns out the rate of earthquakes in Oklahoma has increased by about 50% since October. With 145 quakes measuring 3.0 or above. Increases significantly for the central part of the state. It's hard to say how big an earthquake could be or when that earthquake could happen. Reporter: The ominous warning, the first of its kind for a state east of the rockies. It turns out the earthquake rate in Oklahoma has increased about 50% since October. With 145 quakes measuring 3.0 or above in the first four months of this year. That's more than California saw in the same period of time. One of Oklahoma's first and last major quakes was a magnitude 5.6 in 2011. We literally grabbed the bed to stabilize ourselves. Reporter: While no one was hurt, it highlights what could be a big problem. Unlike states in California, the buildings in Oklahoma are not specifically built to withstand the kind of quake that could hit the sooner state sooner or later. Oklahomans should be thinking about earthquakes. Thinking about preparing for earthquakes. Reporter: Many seismologists blame this increase on fracking, a controversial way of extracting natural gas from the Earth. Now, the industry, which as you might know is very important to the economy down here, vehemently denies that.
This transcript has been automatically generated and may not be 100% accurate.