By CLINT FOSTER
Earthquakes typically bring to mind the Pacific coast more so than North Texas, but tremors rattled two spots very close to Mineral Wells over the night, Thursday, before most locals had even woken up to baste their Thanksgiving turkeys.
The United States Geological Survey reported two earthquakes detected north of Mineral Wells in the wee hours of Thanksgiving morning.
The first, a 3.6-magnitude quake, was recorded at 1:58 a.m. about 10 miles north of the city.
The second registered approximately 15 miles northwest of Mineral Wells in Jack County with a magnitude of 2.8. There have been no reports of damage or injuries.
Brazos River Authority public information officer Judi Pierce said her office completed an inspection of the Possum Kingdom Lake Dam “first-thing” Thursday morning – per an internal policy that the BRA typically inspects the dam after any kind of quake within 60 miles.
Contrary to a report from another area newspaper, Pierce said the BRA is only required to inspect the dam if there is a 4.4-magnitude quake within 15 miles of the lake or a 5.0-or-higher quake within 12 miles, because of stipulations set by the Federal Energy Regulatory Commission.
“We have seen no indication that there was any kind of shifting or cracking [in the dam],” Pierce told the Index. “It’s an abundance of caution for us. We’re expecting there may be more [earthquakes].”
The two local quakes are only the latest in a long line of North Texas Earthquakes this month. In all, 19 tremors have shaken area residents – from Richland Hills to the most recent movement 14 miles southwest of Jacksboro. The bulk of these quakes have been concentrated in the areas around Azle and Springtown. Mineral Wells’ 3.6 quake matched the strongest yet documented this month, with the other 3.6 occurring northwest of Azle, Nov. 19.
Although the 3.6 shocks are by no means the strongest earthquakes in Texas history, based on information from the USGS, they are certainly rare for this area.
District 61 State Representative Phil King (R-Weatherford) told the Index that there is no consensus amongst state geologists concerning a concrete cause for these recent earthquakes. King said although experts agree the tremors are benign, some experts believe they could be connected to the local oil and gas industry.
“There are some studies that suggest a correlation between the saltwater disposal wells and these minor earthquakes,” he said. “I don’t think that anybody legitimately thinks it’s the hydraulic fracturing or drilling itself. On the other hand, nobody really knows. However, what geologists have told me is that these levels of quakes are very common.
For example, West Texas gets them all the time. They’re not at a level anyone should worry about. They are a little bit of a nuisance, but that’s it.”
King said he is skeptical of connections to the oil and gas industry, primarily because of a discrepancy between the depth of the quakes’ epicenters are significantly lower than the depth for drilling and disposal wells in the Barnett Shale. Both earthquakes in the Mineral Wells area occurred at a depth between 2.4 and 3.1 miles below the surface, whereas the average depth for crude oil and natural gas wells tends to be just over a mile, according to statistics from the United States Energy Information Administration.
King added the other half of his skepticism is largely pragmatic.
“There’s really no definitive scientific evidence to say that these earthquakes are caused by the industry,” he said. “There are over a million oil and gas wells in Texas. There are thousands of saltwater disposal wells. There have been tens-of-thousands of instances of hydraulic fracturing. So I’m a little suspicious [of the claim] that it might be causing earthquakes in Springtown.
“We’ve been drilling oil and gas wells for over 100 years, we’ve been doing hydraulic fracturing going on 15 or 20 years, we’ve been using saltwater disposal wells for decades; why is it just now that in North Texas it would be causing earthquakes? That’s why, from a pragmatic standpoint – not being a scientist – I ask a lot of questions.”
King explained that one reason scientists are not certain as to the cause of these recent earthquakes is they simply do not have the equipment necessary to hone in on these tremors at a “micro level.” These “sophisticated and targeted seismic monitors” that may be relatively commonplace in Northern California are few and far between in North Texas.
But King said he believes the cause of these earthquakes – however harmless – will continue to be thoroughly investigated by leading state geologists and researchers.
“I think there’s a lot of focus in the scientific community on this right now,” he said. “There are a lot of papers being written and studies being done. I suspect with all the concerns about it that there will continue to be.
“It is disturbing, I get that, too. All I care about is that the truth and facts be scientifically determined. I don’t want the environmental community trying to use this to shut down our oil and gas production in North Texas. That’s why my insistence is... let’s make absolutely sure there’s hardcore scientific evidence, not just correlations and rhetoric.”