joe wertz, has been reporting on this for "state impact oklahoma," a project of npr member stations. he government of oklahoma and in particular the oklahoma geological service, they have not always admitted that there's a connection between these wells and these earthquakes. >> yeah, that's right. so, you know why federal and university seismologists and scientists have been more definitive on the link to oil and gas activities in these earthquakes, the state agencies, state officials have been less decisive and have, you know up until pretty recently spoken a lot more about natural earthquakes and talked about natural causes for these earthquakes. >> ifill: this is not limited to oklahoma. other states are affected by this, right? >> that's right. lots of states are getting these so-called induced earthquakes. oklahoma, texas colorado ohio. a lot of states have had the impaction linked to oil and gas activity. oklahoma the most. the researchers have focused on finding out what's going on in oklahoma and applying that the other states. >> ifill: despite the scale of the earthquakes,