Oklahoma aftershocks follow 5.6 earthquake

Posted: Updated:

At least four aftershocks were recorded in northern Oklahoma early Sunday, in the wake of Saturday's damaging 5.6 earthquake.

The U,S, Geological Survey recorded smaller quakes with a magnitude of 2.5-2.8, between about 7:15 and 11:40 a.m. All were centered eight to nine miles northwest of Pawnee, in the approximate area of the Saturday morning quake.

Aftershocks on Saturday night were stronger. Three of them between 10:00 p.m. and 11:30 p.m. measured a 3.0 or stronger, with the most powerful at 3.5.

The Associated Press reported Oklahoma Gov. Mary Fallin has declared a state of emergency in Pawnee County. The Saturday quake there matched a 2011 earthquake for the strongest earthquake in recorded state history.

Fallin's order allows state agencies to make emergency purchases for disaster relief and is the first step toward asking for federal assistance, if necessary.

Fallin said in a statement that information is still being gathered and will be reviewed by her coordinating council on seismic activity.

The state of emergency lasts for 30 days and additional counties may be added.

Pawnee County Emergency Management Director Mark Randell said Sunday that emergency officials and the U.S. Geological Survey are examining the area and finding only minor to moderate damage.

The Oklahoma Department of Transportation inspected roads and 180 bridges within a 30-mile radius of the epicenter and says all were found to be safe.

The state Corporation Commission says no major damage has been found by utilities, pipelines, or fuel infrastructure operators in the area and the U.S. Army Corps of Engineers is inspecting dams within a 50-mile radius of the epicenter.

The 37 wastewater disposal wells to be shut down in north-central Oklahoma in the wake of Saturday's quake are just a fraction of the state's total number.

Oklahoma Corporation Commission spokesman Matt Skinner says the wells are among about 4,200 across the state. They're also among the about 700 in a 15,000-square-mile "Area of Interest" created by the commission to address earthquakes in the area near Pawnee.