[thackney]

They have only been doing hydro frac in the area for half a century before this.

I wonder how all those fault lines got in this area before hydro francs ever started?

I wonder why areas that have far more hydro frac and disposal injection do not have quakes?

[dirtboy]

I think they are injecting into very old fault zones in that part of Oklahoma and that is why injection is different there.