North Texans felt some rattling Friday morning after two earthquakes were detected in western Texas.
Reports of shaking stretched into Dallas-Fort Worth from earthquakes recorded about 250 miles away from Dallas, near Hermleigh in Scurry County, according to the United States Geological Survey.
The first earthquake, which occurred just before 9:30 a.m., was recorded as a 5.1. Another nearby, with a magnitude 3.2, was recorded about 10 minutes later. About 10:45 a.m., a third earthquake was observed with a magnitude of 2.7.
The earthquakes are only the latest to shake Texas, with four being recorded near Hermleigh on Monday night. The first earthquake, about 10:38 p.m., had the highest magnitude at 4.9., according to the USGS. The weakest of the four had a magnitude of 2.8. The last earthquake occurred just before midnight.
A magnitude 3.0 earthquake was also recorded on Tuesday. Those earthquakes were likely caused by human activity, and are known as being “induced,” said Justin Rubinstein, a seismologist for the USGS.
The majority of induced earthquakes in Texas are caused by wastewater disposal from oil and gas drilling while others are caused by fracking and a process called secondary recovery, Rubinstein told The Dallas Morning News.
During secondary recovery, also known as enhanced oil recovery, operators inject water or carbon dioxide into an older oil and gas field to pull out more resources, he said. Earthquakes like the ones on Monday and Tuesday were likely caused by that process.
“The [Hermleigh] area has earthquakes going back to the 1970s and these earthquakes are all believed to be induced,” Rubinstein said.
This story is developing and will be updated.