Residents in the north Texas community of Irving were rattled on Tuesday by a series of earthquakes that have many anxious for answers. Within a 36 hour period, the U.S Geological Society registered close to a dozen quakes in the region ranging in intensity from a 2.6-3.7 on the richter scale. Though there were no reports of injury, the tremors drew huge concern in an area where quakes are, historically, rare.

Though the amount of earthquakes in Texas hardly compares to our west coast neighbors, they have been on the rise in recent years, causing many to make a connection between increased seismic activity and the fracking throughout the state.

Related: Is Eagle Ford Oil Production Causing Earthquakes?

Several studies including from SMU and UT in Texas and a USGS study in Ohio have linked earthquakes to wastewater injection wells. But this seems unlikely here since there are no such wells in the county and experts warn against jumping to conclusions.

Whatever the cause, North Texas residents were clearly shaken and taxed emergency response systems with an overwhelming amount of 911 calls. Additionally local school districts went into quick action and initiated mandatory emergency earthquake drills for school children.

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