PAWNEE, Oklahoma - United States Geological Survey officials said they believe Saturday’s earthquake was the strongest ever recorded in Oklahoma, coming in 10 percent stronger than the 2011 quake near Prague.

The USGS said earthquake magnitudes are rounded numbers, so despite the 2011 Prague quake being a 5.6 as well, the USGS said the Pawnee earthquake was bigger.

The USGS is also warning Oklahomans that the state could be in for some very strong aftershocks.

“I don’t mean to be an alarmist, but there could be a high-magnitude 4.0 aftershock so people should be prepared,” said USGS Research Geophysicist Daniel McNamara.

Now, based on aftershock locations, the September 3, 2016 earthquake happened on an unknown fault that has now been activated, USGS officials said.  

That fault intersects with one that the USGS already knew ran through Pawnee.