| Title | Induced seismicity in western Canada linked to tectonic strain rate: implications for regional seismic hazard |
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| Author | Kao, H ; Hyndman,
R; Jiang, Y; Visser, R; Smith, B; Babaie Mahani, A; Leonard, L; Ghofrani, H; He, J |
| Source | Geophysical Research Letters vol. 45, 2018 p. 1-12, https://doi.org/10.1029/2018GL079288  Open Access |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20170316 |
| Publisher | American Geophysical Union (AGU) |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); docx (Microsoft® Word®) |
| Province | Alberta; British Columbia; Northwest Territories; Yukon |
| NTS | 83B; 83C; 83D; 83E; 83F; 83G; 83J; 83K; 83L; 83M; 83N; 83O; 84B; 84C; 84D; 84E; 84F; 84G; 84J; 84K; 84L; 84M; 84N; 84O; 85B; 85C; 85D; 93A; 93B; 93C; 93F; 93G; 93H; 93I; 93J; 93K; 93N; 93O; 93P; 94A; 94B;
94C; 94F; 94G; 94H; 94I; 94J; 94K; 94N; 94O; 94P; 95A; 95B; 95C |
| Area | Canadian Cordillera |
| Lat/Long WENS | -126.0000 -115.0000 61.0000 52.0000 |
| Subjects | geophysics; tectonics; fossil fuels; seismicity; seismic risk; earthquakes; strain analysis; satellite geodesy; tectonic interpretations; tectonic environments; deformation; moment measures; seismic
interpretations; seismic waves; petroleum industry; wells; modelling; Western Canada Sedimentary Basin; Environmental hazards; global navigation satellite systems (GNSS) |
| Illustrations | location maps; geoscientific sketch maps; plots; schematic representations; time series |
| Program | Environmental Geoscience Shale Gas - induced seismicity |
| Released | 2018 10 11 |
| Abstract | A rapid increase of injection-induced earthquakes (IIE) is often linked to a higher level of seismic hazard. In this study, we compare the geodetically defined moment rate to seismicity distribution in
western Canada where significant IIE are observed. The regional seismic pattern is dominated by IIE, both in number and moment, along a 150-km wide NW-SE band of moderate strain rate in the easternmost Cordillera and foothills. The observed rate of
moment release from local earthquakes is much closer to the tectonic moment rate in the IIE-dominated areas. We conclude that, on a regional scale, tectonic strain rate is an important control on IIE. Injection in areas with moderate tectonic strain
may temporarily increase the local seismic hazard, but widespread IIE over an extended period of time may deplete the available tectonic moment and could, under the right conditions, have a limited long-term effect of reducing regional seismic
hazard. |
| Summary | (Plain Language Summary, not published)
We locate earthquakes in western Canada where deep underground fluid injections are performed for the development of shale gas and oil. The seismic
distribution is compared to the location of injection wells to define the band of injection-induced earthquakes (IIE). This band is located in between the eastern Canadian Cordillera, where the tectonic strain rate is the highest, and the Western
Canada Sedimentary Basin, where the tectonic strain rate is very low. We conclude that tectonic strain rate is an important control on IIE. We also found that the amount of energy released by local seismicity in the IIE band can be comparable to the
amount of energy accumulated from tectonic strain. It suggests that widespread IIE may deplete the available tectonic energy and could, under the right conditions, reduce the regional seismic hazard in the long term. However, injection in areas with
moderate tectonic strain may temporarily increase the local seismic hazard and should not be overlooked. |
| GEOSCAN ID | 306389 |
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