There have been a bunch of minor quakes in that area in the past 10 days - 2 weeks.  My cousin is a county emergency management director in Oklahoma and has been posting the notices on Facebook.  It's made me curious as to whether whatever underground fault is causing them is ready to really let go soon.    We had a small quake here in about 1969 that had my undivided attention.  Glad we don't live closer to New Madrid MO.