“We've had just a remarkable number of earthquakes,” Holland said.
He said a new seismologist has been hired at the Oklahoma Geological Survey, Amber Lee Darold, helping to find a reason for the earthquakes.
The cause of the increased seismic activity is under investigation.
“We're continuing to try to understand this and to keep up with the number of earthquakes,” Holland said.
When Holland moved to Oklahoma from Arizona there were 38 earthquakes of magnitude 2.5 or greater felt in 2009.
Then 104 earthquakes were felt in 2010 and 97 quakes in 2011, Holland said, before the number dropped to 64 in 2012.