Regional Seismic Variation

October 22, 2015

Solid Earth & Tectonic Processes

The Williston Basin in the north central U.S. produced fewer earthquakes caused by wastewater injection than Texas, suggesting the link between seismicity and production activities may vary by region. The findings were published in the journal Seismological Research Letters in February 2015.

Ongoing since the 1950s, petroleum and gas production in the Williston Basin, underlying parts of Montana, North Dakota, South Dakota and Saskatchewan in Canada, changed in recent years to include hydraulic fracturing and horizontal drilling. Scientists from The University of Texas at Austin took advantage of new monitoring data to explore the connection between seis­micity and petroleum production near the Bakken Formation, an area of historically low seismicity, but with a recent history of increased hydraulic fracturing and wastewater disposal.

“Why are earthquakes triggered in some areas and not in others? It’s an important question for regulators and the scientific commu­nity,” said Cliff Frohlich, lead author of the study and associate director of the Institute for Geophysics. “Some answers are emerging.”