"OKLAHOMA CITY -- In Oklahoma, now the country's earthquake capital, people are talking nervously about the big one as man-made quakes get stronger, more frequent and closer to major population centers. Next door in Kansas, they're feeling on firmer ground though no one is ready yet to declare victory.

A year ago, the states had a common problem - earthquakes caused by the disposal of wastewater from oil and gas exploration. They chose different solutions. Kansas, following early scientific studies, decided to restrict how much and how fast the wastewater could be pumped back underground. Oklahoma instead initially concentrated on the depth of the wastewater injections.

Developments since then haven't been reassuring in Oklahoma, where a quake knocked out power in parts of an Oklahoma City suburb several weeks ago and where fears are growing that the worst is yet to come. On Friday, about 200 unhappy residents packed a forum at the state capitol convened by critics of the state's response. A governor's task force is studying the problem but officials have so far avoided taking tougher measures."

Seth Borenstein, Kelly P. Kissel, and Sean Murphy report for the Associated Press January 18, 2016. [2]