The number of earthquakes in Oklahoma of magnitude 4.0 or higher is up significantly for the year 2018. However, the overall frequency of quakes is still on the decline.
As The Tulsa World reports, through the end of June this year, the Sooner State saw almost 100 earthquakes of magnitude 3.0 or higher. But that’s down from almost 150 during the same period last year.
However, the state has seen six earthquakes of magnitude 4.0 or higher this year—and that’s already more than were seen during all of last year.
The tally this year includes two earthquake swarms near Enid, as well as a 4.6 magnitude tumbler on April 7th near Perry. That one was the 12th largest in state history.
State seismologist Jake Walter said many of the recent quakes can be attributed to fault lines that were activated in 2014, during the wastewater injection process that accompanies the fracking process.