I am science teacher guys. The Earth is made up of Tectonic Plates. Oceanic plate pushes against Continental plate ALL THE TIME. Meaning that all the plates that make up the crust of the Earth are moving contantly. SLOWLY but still moving. (Some only 1/4 in per year, others as much as 2 inches per year).Eventually enough tension builds up in some of the plates ( or at some point along the plates) that they slip, crack, break or shift. It's just Mother Nature doing her thing. Don't panic... It has been going on for 4.6 billion years.
I do agree with this, but as I recall from school there is no plate line running through the center of OK.
http://www.ogs.ou.edu/pubsscanned/openfile/OF1_2011.pdf