During a span of about 30 hours between the morning of Tuesday, January 6, and the early afternoon of Wednesday, January 7, twelve small earthquakes were confirmed by the United States Geological Survey in the Dallas area. While the tremors, ranging in magnitude from 1.6 to 3.6, have not appeared to cause any injuries or serious damage, local scientists and officials are investigating the causes of the unprecedented amount of seismic activity in the area. Since 2008, the Dallas area has experienced over 100 earthquakes. Prior to 2008, only one earthquake had been recorded in the Fort Worth Basin, which lies beneath the Dallas urban area. A team of researchers led by Professor Brian Stump, a seismologist at Southern Methodist University, is working with local city officials to study the causes of these quakes, although it may be several months before Stump and his team can collect and analyze enough data to make any conclusions.

Although the cause of this latest swarm of earthquakes is currently unknown, some researchers and local residents speculate activities related to hydraulic fracturing could be at least partially to blame, and studies from seismic activity in other parts of the country indicate there is a link between fracking activity and earthquakes. The earthquakes in Texas come just days after researchers, in a new study published in the Bulletin of the Seismological Society of America, concluded that fracking was a cause of 77 small earthquakes (ranging in magnitude from 1.0 to 3.0) between March 4 and March 12, 2014, in the Poland Township, Ohio, area. The study’s lead author, Robert Skoumal, noted that fracking activity “did not create a new fault, [but] rather it activated” a previously unknown one.  The study also concluded that fracking operations have to occur fairly close to faults in order to produce earthquakes; thus earthquakes caused by fracking are “pretty rare,” according to Dr. Michael R. Brudzinski, co-author and seismologist at Miami University.

The Poland Township study comes around six months after a report in the journal Science linked over 2,500 minor earthquakes in Oklahoma to four fracking wells. The Oklahoma earthquakes, according to the report, were likely caused by injecting wastewater back into the ground, sometimes near fault lines, after the wells were fracked.