Inferring rock strength and fault activation from high-resolution in situ Vp/Vs estimates surrounding induced earthquake clusters


  • Marco Pascal Roth Ruhr University Bochum
  • Alessandro Verdecchia Ruhr University Bochum
  • Rebecca M. Harrington Ruhr University Bochum
  • Yajing Liu McGill University



Fluid injection/extraction activity related to hydraulic fracturing can induce earthquakes. Common mechanisms attributed to induced earthquakes include elevated pore pressure, poroelastic stress change, and fault loading through aseismic slip. However, their relative influence is still an open question. Estimating subsurface rock properties, such as pore pressure distribution, crack density, and fracture geometry can help quantify the causal relationship between fluid-rock interaction and fault activation. Inferring rock properties by means of indirect measurement may be a viable strategy to help identify weak structures susceptible to failure in regions where increased seismicity correlates with industrial activity, such as the Western Canada Sedimentary Basin. Here we present in situ estimates of Vp/Vs for 34 induced earthquake clusters in the Kiskatinaw area in northeast British Columbia. We estimate significant changes of up to ±4.5% for nine clusters generally associated with areas of high injection volume. Predominantly small spatiotemporal Vp/Vs variations suggest pore pressure increase plays a secondary role in initiating earthquakes. In contrast, computational rock mechanical models that invoke a decreasing fracture aspect ratio and increasing fluid content in a fluid-saturated porous medium that are consistent with the treatment pressure history better explain the observations.


Atkinson, G. M., Eaton, D. W., Ghofrani, H., Walker, D., Cheadle, B., Schultz, R., Shcherbakov, R., Tiampo, K., Gu, J., Harrington, R. M., Liu, Y., van der Baan, M., & Kao, H. (2016). Hydraulic Fracturing and Seismicity in the Western Canada Sedimentary Basin. Seismological Research Letters, 87(3), 631–647.

Babaie Mahani, A., Kao, H., Atkinson, G. M., Assatourians, K., Addo, K., & Liu, Y. (2019). Ground‐Motion Characteristics of the 30 November 2018 Injection‐Induced Earthquake Sequence in Northeast British Columbia, Canada. Seismological Research Letters, 90(4), 1457–1467.

Babaie Mahani, A., Schultz, R., Kao, H., Walker, D., Johnson, J., & Salas, C. (2017). Fluid injection and seismic activity in the northern Montney play, British Columbia, Canada, with special reference to the 17 August 2015 Mw 4.6 induced earthquake. Bulletin of the Seismological Society of America, 107(2), 542–552.

BC-ER. (2023). Well Lookup and Reports.

Bell, J., & Grasby, S. (2012). The stress regime of the Western Canadian Sedimentary Basin. Geofluids, 12(2), 150–165.

Berger, Z., Boast, M., & Mushayandebvu, M. (2009). The contribution of integrated HRAM studies to exploration and exploitation of unconventional plays in North America. Canadian Society of Petroleum Geologists, Reservoir, 36, 40–45.

Berryman, J. G. (1980). Long-wavelength propagation in composite elastic media II. Ellipsoidal inclusions. The Journal of the Acoustical Society of America, 68(6), 1820–1831.

Beyreuther, M., Barsch, R., Krischer, L., Megies, T., Behr, Y., & Wassermann, J. (2010). ObsPy: A Python Toolbox for Seismology. Seismological Research Letters, 81(3), 530–533.

Bhattacharya, P., & Viesca, R. C. (2019). Fluid-induced aseismic fault slip outpaces pore-fluid migration. Science, 364(6439), 464–468.

Bohnhoff, M., Dresen, G., Ellsworth, W. L., & Ito, H. (2009). Passive Seismic Monitoring of Natural and Induced Earthquakes: Case Studies, Future Directions and Socio-Economic Relevance. In New Frontiers in Integrated Solid Earth Sciences (pp. 261–285). Springer Netherlands.

Brantut, N., & David, E. C. (2019). Influence of fluids on V_p/V_s ratio: increase or decrease? Geophysical Journal International, 216(3), 2037–2043.

Chevrot, S., & van der Hilst, R. D. (2000). The Poisson ratio of the Australian crust: geological and geophysical implications. Earth and Planetary Science Letters, 183(1–2), 121–132.

Christensen, N. I. (1984). Pore pressure and oceanic crustal seismic structure. Geophysical Journal International, 79(2), 411–423.

Cochran, E. S., Ross, Z. E., Harrington, R. M., Dougherty, S. L., & Rubinstein, J. L. (2018). Induced Earthquake Families Reveal Distinctive Evolutionary Patterns Near Disposal Wells. Journal of Geophysical Research: Solid Earth, 123(9), 8045–8055.

Crameri, F. (2021). Scientific colour maps. Zenodo, 7.0.1.

Crotwell, H. P., Owens, T. J., & Ritsema, J. (1999). The TauP Toolkit: Flexible Seismic Travel-time and Ray-path Utilities. Seismological Research Letters, 70(2), 154–160.

Davies, G. R., Watson, N., Moslow, T. F., & MacEachern, J. A. (2018). Regional subdivisions, sequences, correlations and facies relationships of the Lower Triassic Montney Formation, west-central Alberta to northeastern British Columbia, Canada — with emphasis on role of paleostructure. Bulletin of Canadian Petroleum Geology, 66(1), 23–92.

Dawson, P. B., Chouet, B. A., Okubo, P. G., Villaseñor, A., & Benz, H. M. (1999). Three-dimensional velocity structure of the Kilauea Caldera, Hawaii. Geophysical Research Letters, 26(18), 2805–2808.

Deng, K., Liu, Y., & Harrington, R. M. (2016). Poroelastic stress triggering of the December 2013 Crooked Lake, Alberta, induced seismicity sequence. Geophysical Research Letters, 43(16), 8482–8491.

Eaton, D. W., van der Baan, M., Birkelo, B., & Tary, J.-B. (2014). Scaling relations and spectral characteristics of tensile microseisms: evidence for opening/closing cracks during hydraulic fracturing. Geophysical Journal International, 196(3), 1844–1857.

Eyre, T. S., Eaton, D. W., Garagash, D. I., Zecevic, M., Venieri, M., Weir, R., & Lawton, D. C. (2019). The role of aseismic slip in hydraulic fracturing–induced seismicity. Science Advances, 5(8), eaav7172.

Eyre, T. S., Samsonov, S., Feng, W., Kao, H., & Eaton, D. W. (2022). InSAR data reveal that the largest hydraulic fracturing-induced earthquake in Canada, to date, is a slow-slip event. Scientific Reports, 12(1).

Goebel, Thomas H. W., & Brodsky, E. E. (2018). The spatial footprint of injection wells in a global compilation of induced earthquake sequences. Science, 361(6405), 899–904.

Goebel, T.H.W., Weingarten, M., Chen, X., Haffener, J., & Brodsky, E. E. (2017). The 2016 Mw5.1 Fairview, Oklahoma earthquakes: Evidence for long-range poroelastic triggering at >40 km from fluid disposal wells. Earth and Planetary Science Letters, 472, 50–61.

Gosselin, J. M., Audet, P., Estève, C., McLellan, M., Mosher, S. G., & Schaeffer, A. J. (2020). Seismic evidence for megathrust fault-valve behavior during episodic tremor and slip. Science Advances, 6(4).

Gregory, A. R. (1976). Fluid saturation effects on dynamic elastic properties of sedimentary rocks. GEOPHYSICS, 41(5), 895–921.

Gritto, R., & Jarpe, S. P. (2014). Temporal variations of V_p/V_s-ratio at The Geysers geothermal field, USA. Geothermics, 52, 112–119.

Guglielmi, Y., Cappa, F., Avouac, J.-P., Henry, P., & Elsworth, D. (2015). Seismicity triggered by fluid injection–induced aseismic slip. Science, 348(6240), 1224–1226.

Han, D.-H., & Batzle, M. L. (2004). Gassmann’s equation and fluid-saturation effects on seismic velocities. GEOPHYSICS, 69(2), 398–405.

Hashin, Z., & Shtrikman, S. (1963). A variational approach to the theory of the elastic behaviour of multiphase materials. Journal of the Mechanics and Physics of Solids, 11(2), 127–140.

Hsu, Y.-F., Huang, H.-H., Huang, M.-H., Tsai, V. C., Chuang, R. Y., Feng, K.-F., & Lin, S.-H. (2020). Evidence for Fluid Migration During the 2016 Meinong, Taiwan, Aftershock Sequence. Journal of Geophysical Research: Solid Earth, 125(9).

Huber, P. J. (1973). Robust Regression: Asymptotics, Conjectures and Monte Carlo. The Annals of Statistics, 1(5), 799–821.

Hunter, J. D. (2007). Matplotlib: A 2D graphics environment. Computing in Science & Engineering, 9(3), 90–95.

Igonin, N., Verdon, J. P., Kendall, J.-M., & Eaton, D. W. (2021). Large-Scale Fracture Systems Are Permeable Pathways for Fault Activation During Hydraulic Fracturing. Journal of Geophysical Research: Solid Earth, 126(3).

Jarvis, A., Reuter, H., Nelson, A., & Guevara, E. (2008). Hole-Filled Seamless SRTM Data V4: International Centre for Tropical Agriculture (CIAT).

Kennett, B. L. N., & Engdahl, E. R. (1991). Traveltimes for global earthquake location and phase identification. Geophysical Journal International, 105(2), 429–465.

Keranen, K. M., & Weingarten, M. (2018). Induced Seismicity. Annual Review of Earth and Planetary Sciences, 46(1), 149–174.

Kettlety, T., Verdon, J. P., Werner, M. J., & Kendall, J. M. (2020). Stress Transfer From Opening Hydraulic Fractures Controls the Distribution of Induced Seismicity. Journal of Geophysical Research: Solid Earth, 125(1).

Lecocq, T., Caudron, C., & Brenguier, F. (2014). MSNoise, a Python Package for Monitoring Seismic Velocity Changes Using Ambient Seismic Noise. Seismological Research Letters, 85(3), 715–726.

Lin, G. (2020). Spatiotemporal variations of in situ V_p/V_s ratio within the Salton Sea Geothermal Field, southern California. Geothermics, 84, 101740.

Lin, G., & Shearer, P. M. (2007). Estimating Local V_p/V_s Ratios within Similar Earthquake Clusters. Bulletin of the Seismological Society of America, 97(2), 379–388.

Lin, G., & Shearer, P. M. (2021). Spatiotemporal Variations of Focal Mechanism and In Situ V_p/V_s Ratio During the 2018 Kı̄lauea Eruption. Geophysical Research Letters, 48(18).

Liu, T., Gong, J., Fan, W., & Lin, G. (2023). In-situ Vp/Vₚ ratio reveals fault-zone material variation at the westernmost Gofar transform fault, East Pacific Rise. Journal of Geophysical Research: Solid Earth, 128(3).

McNutt, S. R. (2005). Volcanic Seismology. Annual Review of Earth and Planetary Sciences, 33(1), 461–491.

Mesimeri, M., Ganas, A., & Pankow, K. L. (2022). Multisegment ruptures and V_p/V_s variations during the 2020–2021 seismic crisis in western Corinth Gulf, Greece. Geophysical Journal International, 230(1), 334–348.

Nanometrics Inc. (2020). BCER Kiskatinaw Seismic Monitoring and Mitigation Area Velocity Model developed by Nanometrics Inc.

Natural Resources Canada. (2023). Earthquakes Canada, GSC, Earthquake Search (On-line Bulletin).

Norgard, G. T. (1997). Structural inversion of the Middle Triassic Halfway Formation, Monias Field, northeast British Columbia. Bulletin of Canadian Petroleum Geology, 45(4), 614–623.

Omovie, S. J., & Castagna, J. P. (2020). Relationships between Dynamic Elastic Moduli in Shale Reservoirs. Energies, 13(22), 6001.

Peña Castro, A. F., Roth, M. P., Verdecchia, A., Onwuemeka, J., Liu, Y., Harrington, R. M., Zhang, Y., & Kao, H. (2020). Stress Chatter via Fluid Flow and Fault Slip in a Hydraulic Fracturing-Induced Earthquake Sequence in the Montney Formation, British Columbia. Geophysical Research Letters, 47(14).

Peterie, S. L., Miller, R. D., Intfen, J. W., & Gonzales, J. B. (2018). Earthquakes in Kansas Induced by Extremely Far-Field Pressure Diffusion. Geophysical Research Letters, 45(3), 1395–1401.

Pimienta, L., Schubnel, A., Violay, M., Fortin, J., Guéguen, Y., & Lyon-Caen, H. (2018). Anomalous Vp/Vₚ Ratios at Seismic Frequencies Might Evidence Highly Damaged Rocks in Subduction Zones. Geophysical Research Letters, 45(22), 12,210-12,217.

QGIS Development Team. (2022). QGIS Geographic Information System 3.22.3. QGIS Association.

Reuss, A. (1929). Calculation of the flow limits of mixed crystals on the basis of the plasticity of monocrystals. Z. Angew. Math. Mech, 9, 49–58.

Roth, M. P., Kemna, K. B., Harrington, R. M., & Liu, Y. (2022). Source Properties of Hydraulic-Fracturing-Induced Earthquakes in the Kiskatinaw Area, British Columbia, Canada. Journal of Geophysical Research: Solid Earth, 127(3).

Roth, Marco P., Verdecchia, A., Harrington, R. M., & Liu, Y. (2020). High-Resolution Imaging of Hydraulic-Fracturing-Induced Earthquake Clusters in the Dawson-Septimus Area, Northeast British Columbia, Canada. Seismological Research Letters, 91(5), 2744–2756.

Salvage, R. O., & Eaton, D. W. (2021). Unprecedented quiescence in resource development area allows detection of long-lived latent seismicity. Solid Earth, 12(3), 765–783.

Schmid, F., Petersen, G., Hooft, E., Paulatto, M., Chrapkiewicz, K., Hensch, M., & Dahm, T. (2022). Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near-Vertical Fractures Exploited by Ascending Melts. Geochemistry, Geophysics, Geosystems, 23(7).

Schultz, R., Skoumal, R. J., Brudzinski, M. R., Eaton, D., Baptie, B., & Ellsworth, W. (2020). Hydraulic Fracturing-Induced Seismicity. Reviews of Geophysics, 58(3).

Takei, Y. (2002). Effect of pore geometry on Vp/Vₚ: From equilibrium geometry to crack. Journal of Geophysical Research, 107(B2).

Verdecchia, A., Cochran, E. S., & Harrington, R. M. (2021). Fluid-Earthquake and Earthquake-Earthquake Interactions in Southern Kansas, USA. Journal of Geophysical Research: Solid Earth, 126(3), e2020JB020384.

Voigt, W. (1910). Lehrbuch der Kristallphysik:(mit Ausschluss der Kristalloptik) (Vol. 34). BG Teubner.

Wang, B., Harrington, R. M., Liu, Y., Kao, H., & Yu, H. (2020). A Study on the Largest Hydraulic-Fracturing-Induced Earthquake in Canada: Observations and Static Stress-Drop Estimation. Bulletin of the Seismological Society of America, 110(5), 2283–2294.

Wang, B., Verdecchia, A., Kao, H., Harrington, R. M., Liu, Y., & Yu, H. (2021). A Study on the Largest Hydraulic Fracturing Induced Earthquake in Canada: Numerical Modeling and Triggering Mechanism. Bulletin of the Seismological Society of America.

Wang, W., Savage, M. K., Yates, A., Zal, H. J., Webb, S., Boulton, C., Warren-Smith, E., Madley, M., Stern, T., Fry, B., Mochizuki, K., & Wallace, L. (2022). Temporal velocity variations in the northern Hikurangi margin and the relation to slow slip. Earth and Planetary Science Letters, 584, 117443.

Weber, B., Becker, J., Hanka, W., Heinloo, A., Hoffmann, M., Kraft, T., Pahlke, D., Reinhardt, J., Saul, J., & Thoms, H. (2007). SeisComP3 - Automatic and Interactive Real Time Data Processing. Geophysical Research Abstracts.

Wessel, P., Luis, J. F., Uieda, L., Scharroo, R., Wobbe, F., Smith, W. H. F., & Tian, D. (2019). The Generic Mapping Tools Version 6. Geochemistry, Geophysics, Geosystems, 20(11), 5556–5564.

Winkler, K. W., & Nur, A. (1982). Seismic attenuation: Effects of pore fluids and frictional-sliding. GEOPHYSICS, 47(1), 1–15.

Worthington, M. H., & Hudson, J. A. (2000). Fault properties from seismic Q. Geophysical Journal International, 143(3), 937–944.

Yu, H., Harrington, R. M., Kao, H., Liu, Y., Abercrombie, R. E., & Wang, B. (2020). Well Proximity Governing Stress Drop Variation and Seismic Attenuation Associated With Hydraulic Fracturing Induced Earthquakes. Journal of Geophysical Research: Solid Earth, 125(9).

Yu, H., Harrington, R. M., Kao, H., Liu, Y., & Wang, B. (2021). Fluid-injection-induced earthquakes characterized by hybrid-frequency waveforms manifest the transition from aseismic to seismic slip. Nature Communications, 12(1).

Yu, H., Harrington, R. M., Liu, Y., & Wang, B. (2019). Induced Seismicity Driven by Fluid Diffusion Revealed by a Near‐Field Hydraulic Stimulation Monitoring Array in the Montney Basin, British Columbia. Journal of Geophysical Research: Solid Earth, 124.

Zhao, D., Kanamori, H., Negishi, H., & Wiens, D. (1996). Tomography of the Source Area of the 1995 Kobe Earthquake: Evidence for Fluids at the Hypocenter? Science, 274(5294), 1891–1894.



How to Cite

Roth, M. P., Verdecchia, A., Harrington, R., & Liu, Y. (2023). Inferring rock strength and fault activation from high-resolution in situ Vp/Vs estimates surrounding induced earthquake clusters. Seismica, 2(2).




Funding data