The scientists from Southern Methodist University gave a report on their finding to local leaders Friday morning.
Initial results from 20 new seismic monitors installed in the area show the earthquakes are relatively shallow. That explains so many people as far away as Plano can feel them.
They've also been concentrated along a narrow, two-mile line.
That suggests a fault line extending from Irving into West Dallas. It runs from Highway 114 to Walnut Hill Road along the Trinity River.
"This is a first step, but an important one, in investigating the cause of the earthquakes," said SMU seismologist Brian Stump. "Now that we know the fault's location and depth, we can begin studying how this fault moves - both the amount and direction of motion."
The next step is looking for the triggers and determining whether they are natural or manmade.
"Sometimes what triggers an earthquake can be very small, so all of these factors have to be considered when looking for that trigger," said Heather DeShon, another seismologist from SMU.
The report notes two inactive gas wells in the area and one wastewater injection well about eight miles to the northwest. But, the scientists have not yet determined if those wells are causing the quakes.
The U.S. Geological Survey previously pinpointed the locations of the earthquakes in a circular pattern around the old Texas Stadium site. The team from SMU no longer believes that map is accurate.
The closest USGS monitor is 40 miles away and some are as far away as 900 miles, they said.
Read the full report: http://www.smu.edu/News/2015/earthquake-update-06feb2015