Yes, you read that correctly.
On Monday, the U.S. Geological Survey and the Oklahoma Geological Survey announced the increased risk of a damaging earthquake – one larger than magnitude 5.0 – in central Oklahoma.
In a joint statement, the agencies reported that 183 earthquakes of magnitude 3.0 or greater occurred in Oklahoma from October 2013 through April 14, 2014. This compares with an average of only two earthquakes with a magnitude 3.0 or larger per year from 1978 to 2008.
The agencies indicated wastewater disposal by injection in deep geological formations as a contributing factor to the increase in earthquakes.
“The water injection can increase underground pressures, lubricate faults and cause earthquakes – a process known as injection-induced seismicity. Much of this wastewater is a byproduct of oil and gas production and is routinely disposed of by injection into wells specifically designed and approved for this purpose. The recent earthquake rate changes are not due to typical, random fluctuations in natural seismicity rates,” the statement read.
Even with the warning, LiveScience reports that geologists don’t know exactly when or where the state’s next big earthquake will strike and are not putting a number on the increased risk.
"We haven't seen this before in Oklahoma, so we had some concerns about putting a specific number on the chances of it," Robert Williams, a research geophysicist with the USGS Earthquake Hazards Program in Golden, Colorado, told Live Science. "But we know from other cases around the world that if you have an increasing number of small earthquakes, the chances of a larger one will go up."
If wastewater injection is indeed causing earthquakes, the activity could continue or decrease with future changes in well usage in the state.
"We don't know if this earthquake rate is going to continue," Williams said. "It could go to a higher rate or lower, so the increased chances of a damaging quake could change in the future."