A U.S. oil boom dumping wastewater into deep wells has triggered earthquakes in the heartland. Stopping the quakes means shutting down bad wells, experts say.

John Templon and Justine Zwiebel / BuzzFeed News

Jim Greff never thought he'd have to worry about earthquakes. He's the city manager of Prague, a farming town of 2,300 people in the middle of Oklahoma. For decades, earthquakes in the landlocked state were almost as rare as ocean views.

But thanks to a series of quakes apparently triggered by wastewater that the oil industry injects deep underground, Oklahoma has become the most seismically active of the U.S.'s lower 48 states.

So now Greff does worry about earthquakes. He's felt dozens in the last four years. "An earthquake sounds like a sonic boom," he told BuzzFeed News. "There's a noise and then a crumpling sound. You think something hit your house."

Oklahoma is not alone. A slew of unexpected earthquakes in the heartland — in Oklahoma, Texas, Kansas, and Arkansas, in particular — has triggered calls from state and federal scientists to quiet the rumbles, collateral damage from the U.S. boom in unconventional oil drilling.

The jump in quake numbers in Oklahoma is particularly stark. Between 1995 and 2004, it had just 14 earthquakes of magnitude 3 or higher, but over the next decade that number shot up to 860. Texas went from 21 to 74, Kansas 6 to 45, and Arkansas 9 to 70, according to U.S. Geological Survey numbers compiled by BuzzFeed News.

The good news is that man-made earthquakes are preventable, USGS seismic expert William Ellsworth told BuzzFeed News. If enough eyes are watching for early shakes, then wastewater well operators could shut down the high-pressure dumping that triggers big quakes.

View Entire List ›