Two earthquakes rocked the Metroplex late Saturday night. The quake left residents in Irving with cracked driveways and down trees.
"The couch actually shook side to side, it actually, you felt the tremors," said Linda Smith, an Irving resident.
"Five minutes after the hour there was this earthquake, which is 3.4 earthquake five minutes later there was this earthquake, a 3.1," said Cliff Frohlich, a senior research scientist at UT Institute of Geophysics.
Over the summer he released a study about earthquakes and injection wells. According to the map Frohlich showed us, there are several drill sites in the Dallas and Tarrant counties. Contaminated waste from drilling and fracking is pumped in to an injection well which the yellow squares represent.
"So almost all the earthquakes that we saw in this area are close to an injection disposal well. On the other hand lots of wells don't cause earthquakes. Over here in Stevens County plenty of injection wells these yellow squares and we didn't find any earthquakes," said Frohlich.
Frohlich says drilling in the area where the earthquake happened stopped over a year ago. He says that backs up the results from his study that fracking doesn't cause earthquakes but the injection wells could, causing small faults near the earth's surface.
"So in this part of the world it looks like mostly when you have earthquakes there are injection wells nearby but when you have injection wells it doesn't mean you have earthquakes," said Frohlich.