Seismologists also installed a new earthquake-monitoring device in Irving this week, after minor temblors rocked an area which is near the site of the former Dallas Cowboys football stadium.
The first quake at 3:10 p.m. measured 3.5 in magnitude. Another at about 7 p.m. measured 3.6, while tremors at 8:11 p.m. and 8:12 p.m. measured less than 3.0.
The first four happened within an area near the Trinity River that's seen a swarm of mild temblors in recent months.
USGS geophysicist Jana Pursley says Tuesday's quakes were the 'largest since the earthquakes started happening there in the last year.'
According to NBC DFW, a 1.7 earthquake took place close to a Dallas intersection at 9:54pm, and a 2.4 earthquake hit Irving's University of Dallas campus at 10:05pm.
A 1.6 earthquake struck at 11:02pm - and like many of the other quakes, was also in the vicinity of the Trinity River, the affiliate station reported.
The seismic series has left residents on edge, wondering if the situation will get worse and what has been behind an uptick in quakes over the last several years.
'The safety and security of our residents is paramount for the city of Irving,' said Irving City Manager Chris Hillman.
Some residents believe the implosion of Texas Stadium in 2010 may have exacerbated problems. There is also speculation the quakes might be related to hydraulic fracturing, or 'fracking,' an energy extraction technique that has a long history in north Texas.
Irving, headquarters of Exxon Mobil's XTO unit that helped pioneer hydraulic fracturing in the region, has two gas wells that were fracked in 2010, according to city officials.
The study by seismologists from Southern Methodist University in Dallas is aimed at pinpointing the quakes' epicenters, said SMU seismology professor Brian Stump.
