The study authors took a different approach in the new work — they hunted for deformed faults below Texas.
The Washington Post covered the landmark earthquake research of a team of SMU geophysicists led by SMU Associate Professor Beatrice Magnani in the SMU Department of Earth Sciences.
The researchers tapped seismic data to analyze earthquakes in Texas over the past decade.
The results of the analysis showed that human activity is causing the earthquakes as a result of movement in faults that have been silent for at least 300 million years, until recent injection of oil and gas wastewater.
The article by journalist Ben Guarino, “Oil and gas industry is causing Texas earthquakes, a ‘landmark’ study suggests,” published Nov. 24, 2017.
By Ben Guarino
The Washington Post
An unnatural number of earthquakes hit Texas in the past decade, and the region’s seismic activity is increasing. In 2008, two earthquakes stronger than magnitude 3 struck the state. Eight years later, 12 did.
Natural forces trigger most earthquakes. But humans are causing earthquakes, too, with mining and dam construction the most frequent suspects. There has been a recent increase in natural gas extraction — including fracking, or hydraulic fracturing, but other techniques as well — which produces a lot of wastewater. To get rid of it, the water is injected deep into the ground. When wastewater works its way into dormant faults, the thinking goes, the water’s pressure nudges the ancient cracks. Pent-up tectonic stress releases and the ground shakes.
But for any given earthquake, it is virtually impossible to tell whether humans or nature triggered the quake. There are no known characteristics of a quake, not in magnitude nor in the shape of its seismic waves, that provide hints to its origins.
“It’s been a head-scratching period for scientists,” said Maria Beatrice Magnani, who studies earthquakes at Southern Methodist University in Dallas. Along with a team of researchers at the U.S. Geological Survey, Magnani, an author of a new report published Friday in the journal Science Advances, attempted to better identify what has been causing the rash of Texas quakes.
A cluster of earthquakes around a drilling project can, at best, suggest a relationship. “The main approach has been to correlate the location to where there has been human activity,” said Michael Blanpied, a USGS geophysicist and co-author of the new study.