This map shows U.S. earthquakes of magnitude 3.0 and higher since 2000. Until 2009, earthquakes that people could feel were rare in Oklahoma. But by 2014, Oklahoma had more than three times as many earthquakes as California.

We also used sound to illustrate the craziness of Oklahoma’s rising rate of earthquakes in the past 10 years.

In this episode of Reveal, I teamed up with Joe Wertz of StateImpact Oklahoma. We traveled around the state to talk to the people who regularly deal with the tremors. We also spoke to experts to gain a better picture of Oklahoma’s man-made earthquakes.

A lot of the quakes are small, but some towns are seeing one almost every day, and seismologists warn that large and damaging earthquakes are becoming more likely. The government in the Sooner State has only recently acknowledged the scope of the oil and gas industry’s role in the problem.

Michael Corey is Reveal's senior data editor. He leads a team of data journalists who seek to distill large datasets into compelling and easily understandable stories using the tools of journalism, statistics and programming. His specialties include mapping, the U.S.-Mexico border, scientific data and working with remote sensing. Corey's work has been honored with an Online Journalism Award, an Emmy Award, a Polk Award, an IRE Medal and other national awards. He previously worked for the Des Moines Register and graduated from Drake University. He is based in Reveal's Emeryville, California, office.