( CNN ) -- On Saturday and Sunday in Oklahoma , there were seven earthquakes . You read that right . Not tornadoes . Earthquakes . The most severe temblor registered 4.3 near Langston , the U.S. Geological Survey site showed , delivering a rumble to Logan County , north of Oklahoma City , according to the U.S. Geological Survey . There were no reports of damage or major injury on Saturday , Oklahoma City news station News9 reported . The three earthquakes that happened Sunday occurred near Langston , CNN affiliate KOCO reported , one registering 4.0 . The station is covering Sunday 's temblors as a developing story . Track the USGS 's earthquake report list . Damage and injury are far more likely with quakes that register 4.0 and higher , the USGS reports . The temblors seem to be part of a trend in the state . As of last month , Oklahoma had surpassed California in the number of earthquakes . From 1978 to 2008 , Oklahoma was hit with an average of just two quakes of 3.0 magnitude of greater . As of June 19 , 2014 , there were 207 such quakes recorded in the state , the USGS said . An increase began in 2009 when 20 quakes of 3.0 magnitude or higher occurred , followed by 43 the next year and increasing every year except for 2012 . As of June 16 , 2014 , California had recorded about 140 quakes of 3.0-magnitude or greater , compared with Oklahoma 's 207 . `` Earthquakes are going to be a normal part of everyday life in Oklahoma , '' CNN meteorologist Chad Myers said . `` They are going to become more and more a part of life there . '' Oklahoma out-quakes California in 2014 . The four quakes that struck Saturday were relatively shallow , happening 5 miles or less from the surface , Myers notes . Larger earthquakes , such as the ones that happen in California , generally go much deeper , sometimes 50 miles deep . The Oklahoma quakes were strong enough to knock dishes off shelves and cause cracks in foundations but not enough to knock down buildings , Myers said . The Oklahoma Geographical Survey said it had stepped up the number of monitoring stations in the state , operating a network of 15 permanent stations and 17 temporary stations . Along with the USGS , the state geographical survey is researching to determine why earthquakes are happening more frequently . It 's possible that hydraulic fracturing , or fracking , could have played a role in causing temblors , but there 's no way to be sure until the USGS files its findings , Myers said . It does that once a month . Fracking is controversial and has split public opinion . CNN explored the process in-depth in an August 2013 special . In short , fracking works like this : A well is typically drilled between 5,000 to 20,000 feet into the earth 's crust , then turns 90 degrees and continues horizontally for several thousand feet to where shale containing natural gas is believed to be . A mix of water , sand and chemicals is pumped at high pressure into the well to create long , narrow cracks or openings in the earth through which gas can escape . The sand particles keep the fissures open , allowing for natural gas to escape from the shale and flow into the well . The gas , along with the waste water , is drawn back up the well to the surface , where it is processed , refined and shipped . Wastewater injection could be behind the increase in the number of quakes recorded in Oklahoma , USGS geophysicist Rob Williams told CNN . Could a larger earthquake happen in the state ? `` Given the rate of earthquakes over the last six months , '' Williams said , `` it 's concerning enough to be worried about a larger , damaging earthquake happening . '' What to know about earthquakes . Measuring the magnitude of earthquakes . Mariano Castillo and Marlena Baldacci contributed to this report .
The largest quake registered a magnitude of 4.3 , according to the U.S. Geological Survey . The temblors appear to be part of a trend of increasing earthquakes in Oklahoma . No major injuries or damage was reported from Saturday 's quakes , news station says .