"Oklahoma was struck by a magnitude 5.1 earthquake on Saturday morning, the third-strongest quake ever recorded in the state, which has experienced a surge in seismic activity in recent years, the U.S. Geological Survey reported.

The quake at 11:07 a.m. local time (1707 GMT) was followed by several aftershocks in the next 90 minutes, including one with a magnitude of 3.9, the USGS said. The first quake was felt from Kansas City, Missouri, to Dallas, Texas, but no damages or injuries were reported.

Oil fields have boomed in Oklahoma over the past decade thanks to advances in hydraulic fracturing and horizontal drilling, and seismologists have said the state's frequent earthquakes may be linked to disposal wells that inject saltwater, a natural byproduct of oil and gas work, into deep underground caverns."

Fiona Ortiz and Letitia Stein reports for Reuters February 13, 2016. [2]