OKLAHOMA CITY (AP) - Scientists say Oklahoma recorded 222 earthquakes with magnitudes of 2.5 or greater last year, soaring above 2012's total of 64 temblors.
And 2014 is already off to a busy start - the state has recorded 63 earthquakes so far at 2.5-magnitude or greater, according to The Oklahoman. That total doesn't include several earthquakes that struck Logan County late Sunday and early Monday.
The cause of the increase in seismic activity is under investigation.
Seismologist Austin Holland with the Oklahoma Geological Survey says there were 97 quakes at 2.5-magnitude or greater in 2011, and 104 such quakes in 2010.
Oklahoma's strongest recorded earthquake was a 5.6-magnitude quake that struck in November 2011 near Prague. It damaged 200 buildings, shook a football stadium and rattled parts of seven states.
(Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)