Feb 13 Two earthquakes, one with a magnitude 5.1 and the other of 3.9, struck northern Oklahoma on Saturday morning and were felt through much of the state but no damages were immediately reported, the U.S. Geological Survey and local media said.
Both quakes were centered about 95 miles (153 km) northwest of Oklahoma City. The first quake hit at 11:07 local time (1707 GMT), and the second one came about 10 minutes later, the USGS said.
The larger earthquake was "probably the second largest in Oklahoma and the largest in this general area," said John Bellini, a geophysicist at the USGS National Earthquake Information Center.
Bellini said Oklahoma's previous largest was a 5.6 earthquake in 2011. It was not known if Saturday's quake was related to oil production activities, he said.
The first quake was felt across central and northern Oklahoma, Tulsa's News On 6 television reported. The TV station said no injuries or damages had been reported.
Oklahoma has seen a surge in seismic activity in recent years, which seismologists have said may be linked to oil production activities.
The state has been recording 2.5 earthquakes daily of a magnitude 3 or greater, a rate 600 times greater than observed before 2008, the Oklahoma Geological Survey said in a report last year.
The tremor was registered just after 11 am local time (5 pm GMT). A 3.9-magnitude aftershock was reported 10 minutes later.
5.1 mag. earthquake 28 mi NW of Fairview, @ 11:07 am EST this morning
The epicenter of the earthquake was located about a mile (1.6 km) beneath the ground some 95 miles (153 km) northwest of Oklahoma City, according to USGS. The town of Fairview was the closest to the epicenter, which is located 17 miles (28 km) away.
There have been no immediate reports of damage or casualties.
According to USGS, most of North America east of the Rocky Mountains normally experiences earthquakes infrequently. In some regions, a “significant majority” of the earthquakes taking place recently are thought by researchers to have been triggered by human activities, such as mining and other of natural resource extraction that could be altering conditions in the Earth’s crust.
It’s not immediately known if Saturday’s tremor is related to oil production activities, USGS’s Bellini said.
In January, local authorities announced that nearly $1.4 million of the state’s emergency fund would be allocated to the Oklahoma Corporation Commission and the Oklahoma Geological Survey for seismic research at the request of Oklahoma Governor Mary Fallin, who said better understanding of what is causing the recent earthquakes in the state is needed.