title: Fault activation by hydraulic fracturing in western Canada.
abstract: Hydraulic fracturing has been inferred to trigger the majority of injection-induced earthquakes in western Canada, in contrast to the Midwestern United States, where massive saltwater disposal is the dominant triggering mechanism. A template-based earthquake catalog from a seismically active Canadian shale play, combined with comprehensive injection data during a 4-month interval, shows that earthquakes are tightly clustered in space and time near hydraulic fracturing sites. The largest event [moment magnitude (MW) 3.9] occurred several weeks after injection along a fault that appears to extend from the injection zone into crystalline basement. Patterns of seismicity indicate that stress changes during operations can activate fault slip to an offset distance of >1 km, whereas pressurization by hydraulic fracturing into a fault yields episodic seismicity that can persist for months.
authors.affiliation: Department of Geoscience, University of Calgary, Calgary, Alberta T1N 1N4, Canada.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Bao
authors.affiliation: Department of Geoscience, University of Calgary, Calgary, Alberta T1N 1N4, Canada. eatond@ucalgary.ca.
authors.forename: David W
authors.initials: DW
authors.lastname: Eaton