"More And Bigger Drilling-Linked Earthquakes Rattle Oklahoma"

"OKLAHOMA CITY -- Several earthquakes shook Oklahoma on Monday as the state experiences a sharp increase in the frequency of tremors linked to wastewater disposal from gas and oil drilling, including from fracking, state and federal officials said.

Three of Monday's quakes measured above a magnitude 4.0, with a 4.5 earthquake centered just north of Crescent, roughly 45 miles (72 km) north of Oklahoma City, the U.S. Geological Survey (USGS) said.

The largest tremor, logged a "significant earthquake" by the USGS, could be felt as far away as Wichita, Kansas, about 160 miles north, broadcaster KOTV reported."

Heide Brandes reports for Reuters July 28, 2015.