Oklahoma had more earthquakes in 2015 than every continental state combined,reports Oklahoma City station KOCO.49 U.S. states—excluding the massive Alaska—recorded a total of almost 1,600 earthquakes of magnitude 3 or greater last year. Of those, almost 900 were in Oklahoma. The other states had a combined total of 729.
The Sooner State has been shattering its own records every year. In 2013, the state had just over 100 earthquakes, 72 more than the year previous. Then, from 2013 to 2014, the state leapt from 106 to 585. That’s an increase of almost 500 quakes in a single year. And now Oklahoma has broken that record.
Researches have concluded that the quakes are due to the disposal of drilling wastewater during the fracking process.