5.6 earthquake shakes central Oklahoma

A rare 5.6 earthquake considered to be the strongest on record in the area shook the central US state of Oklahoma, reportedly causing significant damage.

After initially putting the magnitude of the last night temblor at 5.2, the US Geological Survey revised the strength of the seismic event, the second of the day, saying it had reached magnitude 5.6. The first 4.7-magnitude jolt was reported north of the town of Prague yesterday.

The epicentre of the tremor, which occurred at 10:53 pm local time (0923 IST today), was located just six kilometres east of the town of Sparks at a depth of five kilometres.

KJRH television said the Lincoln County Emergency Management agency was reporting significant damage, but offered no details.

The readings were based on the open-ended Moment Magnitude scale, now used by US seismologists, which measures the area of the fault that ruptured and the total energy released.

The Oklahoman newspaper said the quake was felt as far as north Texas.

"The picture by the TV fell off the wall and we jumped up because we thought somebody had hit the house," the paper quoted Oklahoma City resident Noeh Morales as saying. "It was like a roaring noise. I've never heard one that bad over here."

Oklahoma City is located 72 kilometres from the epicentre of the quake.