West Texas quakes occur near drilling sites, SMU finds

Driving the news: Two earthquakes in West Texas late last month were felt more than 200 miles away in downtown Dallas.

• Both were among the strongest ever recorded in Texas, per FOX4.

Flashback: More than 100 earthquakes were recorded within a week in July around Scurry County in West Texas, per the Dallas Morning News. But only the higher-magnitude ones were felt in Dallas-Fort Worth.

• Not all tremors are confined to West Texas oil fields. A 3.0- and a 3.2-magnitude earthquake were recorded on the same afternoon in May just outside Mansfield.

How it works: Oil and gas companies use water to break up, or fracture, rock formations to let loose natural gas. That water then flows back to the surface but is no longer suitable for drinking.

• The process, known as fracking, ends with companies collecting the wastewater, which is often then injected into natural underground porous rock formations, per the Environmental Protection Agency.

What they found: The injection well sites, where that wastewater is stored underground, cause earthquakes nearby, SMU researchers found.

• Recent research has primarily focused on Texas temblors occurring after 2017, when the Texas Seismological Network was established and started monitoring quakes at lower magnitudes.
• The updated SMU research was able to reassess pre-2017 earthquakes and found that low-magnitude quakes also occurred near injection wells.

The bottom line: Texas and Oklahoma have seen an increase in human-caused earthquakes since 2009, when fracking became prevalent in oil and gas drilling.