US Geological Survey upgrades Pawnee quake to 5.8 magnitude; upgrades 2011 Prague quake

Earthquake

PAWNEE, Okla. – It was a wake up call for thousands of Oklahoma residents, and even some people in other states.

Shortly after 7 a.m. on Saturday, a 5.6 magnitude earthquake was recorded by the U.S. Geological Survey near Pawnee.

That would tie Saturday’s earthquake with the earthquake that hit Prague in 2011, which damaged homes and buildings in Lincoln and Pottawatomie counties.

On Wednesday, the U.S. Geological Survey announced that it is updating the official magnitude of the quake from a 5.6 to a 5.8 magnitude, sealing its fate as the largest recorded earthquake to date.

However, the USGS said it is also going to update the earthquake that hit Prague on Nov. 6, 2011 from a 5.6 magnitude to a 5.7 magnitude.

Officials say they decided to update the quakes after reanalyzing both earthquakes.

“USGS analyses indicate that the two earthquakes are very similar in size – to within typically-cited uncertainties of 0.1 magnitude units,” said Gavin Hayes, USGS research geophysicist. “However, the 2016 Pawnee event is slightly larger than the Prague earthquake in 2011,” noted Hayes.

“While the difference in size between the two events is less than 0.1 magnitude units,” Hayes continued,  “rounding magnitudes to one decimal place means that the magnitude of the Prague earthquake is Mw 5.7, and the Pawnee earthquake is Mw 5.8.”

In response to the quake, the Oklahoma Corporation Commission told disposal well operators within 725 square mile area around the location of quake to shut down their wells.

That involves around 37 wells.