Oklahoma surpasses California in number of earthquakes

California has long been considered as a place of frequent earthquakes, but Oklahoma has easily surpassed the Golden State in the number of quakes this year.

On Thursday morning, Oklahoma suffered five earthquakes that rattled an area of the state where oil & gas drilling, otherwise known as hydraulic fracturing or fracking, is prevalent.

The five tremors/quakes were of magnitudes higher than 3.0, the magnitude at which quakes can easily be felt by humans. So far this year, Oklahoma has suffered nearly double the number of quakes as California. While California suffered 88 earthquakes of a magnitude of 3.0 or greater, Oklahoma recorded a total of 174 quakes.

While seismic activity in California is spread throughout the state, quakes in Oklahoma are concentrated in the central & northern parts of the state, where fracking activities have doubled between 2009 and 2012.

Mae Emerson, a resident of Guthrie, said, "To me, it's kind of scary. I mean, just to start happening . there's got to be a reason for it, you know. Why is this happening all of a sudden?"

Before 2009, Oklahoma recorded an average of one quake per year, but the number has increased to at least one per day.

Hydraulic fracturing or fracking is a process of injecting water, sand and certain chemicals deep under the surface of the earth to break rocks and release trapped gas and oil. The controversial process not only creates tremors in the area but also poses threat to environment as it can pollute underground water.