Recent quakes explained as "aftershocks" from earthquake months ago
NORMAN, Okla. (KFOR) - The Oklahoma Geological Survey said there was a good explanation for why the metro continues to feel earthquakes. Jake Walter, state seismologist, said they were aftershocks linked to two big earthquakes earlier in the year: a 4.4 magnitude near Edmond in January and a 5.1 magnitude in Prague in February.
"We can expect that the aftershocks will continue for several months," said Walter.
He said there have been at least 2,500 aftershocks in Prague and more than 150 in the Edmond/Arcadia area.
Walter said most of those no one can feel. He said the Oklahoma Geological Survey can measure more aftershocks in the Prague area because it has more equipment focused on that region.
It has still been a mystery as to what caused the initial January quake in Edmond.
“We’re still examining the available data,” said Walter. “Both of those fault zones actually have a long history of being active.”
The Oklahoma Corporation Commission said it stopped allowing wastewater disposal in the area near Edmond years ago, after quakes started rocking the metro. However, it was allowed near Prague. After the February earthquake there, the OCC immediately requested a wastewater disposal stop. They told KFOR that their inspectors check the area often and have not seen any illegal operations.
The Oklahoma Geological Survey said it was also keeping tabs on disposal activity.
"We have confirmed that with sort of our independent analysis of their data sets,” said Walter. “We're continuing to see a decline again in the earthquake magnitudes and frequencies."