The devastating earthquakes that rocked West Texas in recent days were likely caused by oil and gas activity in a region that has been experiencing tremors for decades, according to the United States Geological Survey (USGS).
A streak that began in 2021 was marked Friday by its largest quake, measuring 5.1 magnitude, in the country’s most active zone for oil and gas-induced earthquakes, experts said. The recent quakes have damaged homes, infrastructure, power lines and other property, weakening foundations and cracking walls and ceilings, officials said.
No injuries were reported, the city of Snyder’s emergency management office said on Facebook. Authorities declared a disaster in Scurry County.
“Safety is our top priority for all of our residents, so we wanted to make sure we had all the resources available at our fingertips if we needed them,” said Jay Callaway, emergency management coordinator for the city of Snyder and Scurry County. He added that despite residents’ concerns, a disaster declaration does not mean they were expecting a “major disaster.” He said the area continued to experience small tremors Monday.
There were more than 50 earthquakes of magnitude 3 or greater — the smallest earthquakes typically felt by people are magnitude 2.5 to 3 — during this multi-year sequence, Robert Skoumal, a research geophysicist at the USGS, said in an email. A sequence is typically a series of earthquakes in a particular region attributable to the same activities, he explained.
Although Friday’s was the strongest in the sequence, officials also recorded a recent 4.5 quake, a 4.9 on July 23 and a 4.7 last year. A water main ruptured in the town of Snyder due to an earthquake last week, Callaway said, but the problem has been repaired.
“This particular part of the Permian Basin has a long history of earthquakes caused by oil and gas operations, dating back to at least the 1970s,” Skoumal said.
The Permian Basin, which stretches from southeastern New Mexico to most of West Texas, is a vast basin known for its rich deposits of oil, natural gas and potassium and is made up of more than 7,000 fields in West Texas. It is the most active area of induced earthquakes in the country and probably the world, according to the USGS. There are many ways humans can cause or induce earthquakes, but the vast majority of earthquakes in this category in the central United States are driven by oil and gas operations, Skoumal said.
A region that is not naturally seismic
Earthquakes were first introduced to the region by a process in which water is injected into the ground to increase production from oil reservoirs.
Four other earthquakes greater than magnitude 5 have struck West Texas in recent years. The strongest was 5.4. “All four of those earthquakes were caused by sewage disposal,” Skoumal said.
Further analysis is needed to confirm the precise cause of the earthquakes in the area, but since the region is not naturally seismic and has a long history of induced earthquakes, “these recent earthquakes were likely also caused by oil and gas operations,” Skoumal said.
Oklahoma experienced a dramatic increase in earthquakes in the early 2010s, which researchers have linked to wastewater from oil and gas extraction that was injected deep into the ground, activating ancient faults deep in the Earth’s crust. Wastewater comes from oil and natural gas production and includes salt water, drilling fluids and other mineralized waters.
A sharp increase in earthquakes in Oklahoma more than a decade ago led state regulators to impose restrictions on sewage disposal, particularly in areas around the epicenter of the quakes. Since then, the number of earthquakes has begun to decline significantly.