The chart above uses information from the Bureau of Economic Geology at the University of Texas. It shows that the number of magnitude 3 earthquakes (or greater) more than doubled in Texas in 2021 (from slightly less than 100 to more than 200). Texas has never been a hotspot for earthquakes, but the oil companies are changing that by their use of fracking.
The following is part of an article by Erin Douglas in The Texas Tribune:
More than 200 earthquakes of 3 magnitude and greater shook Texans in 2021, more than double the 98 recorded in 2020, according to a Texas Tribune analysis of state data maintained by the Bureau of Economic Geology at the University of Texas at Austin.
The record-setting seismic activity is largely concentrated in West Texas’ Permian Basin, the most productive oil and gas region in the state. Scientific studies show that the spike in earthquakes is almost certainly a consequence of disposing huge quantities of contaminated, salty water deep underground — a common practice by oil companies at the end of the hydraulic fracturing process that can awaken dormant fault lines.
During hydraulic fracking, oil companies shoot a mixture of fluids and sand through ancient shale formations, fracturing the rock to free the flow of oil. But oil isn’t the only thing that’s been trapped underground for millions of years: Between three and six barrels of salty, polluted water also come up to the surface with every barrel of oil.
The cheapest, and most commonly used, way to dispose of this “produced water” is to drill another well and inject it into porous rock formations deep underground.
For years, oil companies have loaded those formations with hundreds of millions of gallons of the black watery mixture — which contains a slurry of minerals, oil and chemicals used in fracking — every day, slowly increasing the pressure on ancient fault lines. An analysis by Rystad Energy provided to The Texas Tribune found that the amount of wastewater injected underground in the Permian Basin quadrupled in a decade, from 54 billion gallons in 2011 to 217 billion gallons last year.
In a 2021 study published in the Journal of Geophysical Research, scientists at the U.S. Geological Survey and the University of Texas found that the vast majority of seismicity since 2000 near Pecos — a city roughly 100 miles southwest of Midland — was likely triggered by increased wastewater disposal. State regulators, too, have found that an increase in seismic activity most likely occurs as a consequence of saltwater disposal.
“The cumulative volumes [of water] increase the pressure, and that is the force that triggers the fault to slip,” said Alexandros Savvaidis, a research scientist at the Bureau of Economic Geology at UT-Austin.
The result is that communities like Gardendale, where Bock lives, as well as the bustling cities of Odessa and Midland — which many oilfield workers, engineers and service workers call home — are experiencing not only more frequent earthquakes, but stronger ones.
Between 2018 and 2020, Texas recorded nine earthquakes above magnitude 4, almost all of them in the western half of the state. Last year, Texans were shaken by 15 earthquakes above magnitude 4 — including a 4.6 magnitude earthquake in late December that rattled homes from an epicenter about 30 miles northeast of Midland.
