California is generally perceived to have the most seismic activity in the U.S., due to being located on the San Andres Fault Line. However, the Midwest has experienced significantly more earthquakes than California so far in 2016.
Oklahoma has had 1,502 earthquakes at or above a magnitude of 2.5 since 2016 began. For the area in and around California, this number is much lower, at 711 earthquakes.
Notably, a 5.8 magnitude earthquake hit Pawnee, OK on September 3, 2016. This was the largest recorded earthquake in the state’s history, according to the United States Geological Survey (USGS). This sizeable quake was felt in up to seven states based on information gathered and recorded by the USGS, including Oklahoma, Kansas, Arkansas, Missouri, Texas, Nebraska, and Iowa.
The number of earthquakes in Oklahoma has been rapidly increasing in recent years. In 2013, Oklahoma experienced only 109 earthquakes above a 3.0 magnitude. In 2016 so far, there have been over 1,500.
The increase of seismic activity has caused many to believe that the number of quakes is not rising due to natural causes, but because of wastewater disposal wells. After the 5.8 magnitude earthquake on September 3, the governor of Oklahoma
shut down wells in the affected area after declaring a state of emergency. The 3,200 disposal wells in the state are now considered to be a serious threat for the Midwest.
Many researchers have speculated that the increase of earthquakes in Oklahoma has been caused by fracking, a process used to extract oil and natural gas from inside of the earth.
“Fracking is not causing most of the induced earthquakes. Wastewater disposal is the primary cause of the recent increase in earthquakes in the central United States,” said the USGS.
The Oklahoma Corporation Commission and the Oklahoma Geological Survey have received $1.4 million in emergency funds and are actively working towards finding potential solutions to the rising amount of quakes.