A report and maps released by Geoscience BC today provides new information about where there's an increased potential of amplification of ground motion from earthquakes associated with hydraulic fracturing and fluid disposal in Northeast B.C.'s Montney play.
The research can be used to better anticipate movement at the surface.
The report’s recommendations include collecting more high-quality geotechnical and other borehole data to refine geotechnical mapping and acquiring additional shear-wave velocity data to improve models of the subsurface.
Called Mapping the Susceptibility to Amplification of Seismic Ground Motions in the Montney Play Area of Northeast British Columbia, the report focuses on understanding where seismic waves can, in some situations, be amplified due to local shallow geological conditions.
A team of researchers from Monahan Petroleum Consulting, Quaternary Geosciences Inc., Petrel Robertson Consulting Ltd., Frontier Geosciences Inc. and the University of Victoria compiled technical information from surface geology maps and boreholes. They produced a preliminary map of the soils, sands and gravels in the Peace region, and indicated which units are more likely to amplify seismic ground motions. The report grades areas in the Montney development area according to the National Earthquake Hazards Reduction Program standard developed by United States federal agencies.
“Hydraulic fracturing rarely causes earthquakes that are felt at surface, according to data from regulators. Nonetheless, understanding where amplified seismic ground motions are more likely to occur is important for public safety and protection of infrastructure,” said project lead Patrick Monahan of Monahan Petroleum Consulting. “Seismicity has increased in northeastern B.C. in recent years due to hydraulic fracturing and fluid injection associated with natural gas production. This project identifies areas where amplified ground motions could occur.”
“This report shows how geology can dictate why smaller earthquakes are sometimes felt at the surface because seismic waves can be amplified as they travel through the ground,” said Geoscience BC Executive vice-president and chief scientific officer Carlos Salas.
“This new research can help industry, regulators, communities and First Nations better understand areas with the potential of increased ground motion associated with natural gas extraction in the Peace River Regional District, thereby improving industry processes and protocols to manage felt events.”