Fracking-caused quakes in Oklahoma?

As Rachel noted on the show the other day, it’s not unusual for Oklahoma to experience some seismic activity. Looking back over the last several years, the state has seen between 40 and 100 meaningful earthquakes – quakes with a magnitude of 2.5 or more – per year. Last year, that figure more than doubled to over 200 earthquakes.
 
And this year, as of Tuesday, there have already been 103 quakes with a magnitude of 2.5 or more, putting Oklahoma on track to reach more than 780 significant earthquakes this calendar year – and that total doesn’t include the small ones of lower magnitude.
 
This has not gone unnoticed in the Sooner State, where many are beginning to wonder whether the seismic activity is more than just a random fluke. Public Radio Tulsa had this report yesterday.
Geologists are increasingly looking at waste water disposal wells as the cause of earthquakes linked to oil drilling.
 
A report from the National Academy of Sciences says injection wells are the likely cause of earthquakes linked to oil production, including in Oklahoma.
Yep, the question at hand is whether fracking is causing an extraordinary spike in the frequency of significant earthquakes. And it’s not just Oklahoma that wants an answer.
 
It is certainly possible that there’s an unrelated cause that explains why Oklahoma is on pace for more than 780 significant earthquakes this year. That said, recent developments in Texas are worth considering as the discussion unfolds. Take a look at Rachel’s segment from Tuesday:
 

Fracking and Oklahoma

Fracking-caused quakes in Oklahoma?