1. Quantification of potential macroseismic effects of the induced seismicity that might result from hydraulic fracturing for shale gas exploitation in the UK
by Rob Westaway, and Paul L. Younger
Quarterly Journal of Engineering Geology and Hydrogeology
Volume 47(4):
November 1, 2014
© 2014 The Authors

2. Amplitudes of ground vibrations that might cause hazard or nuisance.
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors

3. Comparison of regulations for peak ground velocity at residential property from quarry blasting, applicable in the UK, with felt effects, proposed magnitude thresholds for regulating ‘fracking’ in the UK, estimates of PGV from various other forms of environmental nuisance, and predictions of vertical and horizontal PGV from Bragato & Slejko (2005) and from the spectral method developed in this study.
Comparison of regulations for peak ground velocity at residential property from quarry blasting, applicable in the UK, with felt effects, proposed magnitude thresholds for regulating ‘fracking’ in the UK, estimates of PGV from various other forms of environmental nuisance, and predictions of vertical and horizontal PGV from Bragato & Slejko (2005) and from the spectral method developed in this study. All predictions are for points on the Earth’s surface directly above ‘fracking’ at a depth of 2.5 km, so R = 2.5 km; the two sets of predictions after Bragato & Slejko (2005) correspond to the original (lower) and ‘doctored’ (higher) versions of their equations, both versions being calibrated for ML ≥ 2.5 and extrapolated to lower magnitudes for illustrative purposes only. All predictions for the spectral method developed in this study assume μ = 12.7 GPa, ν = 0.18, ρ = 2550 kg m−3, vs = 2.15 km s−1, b = 1.6, η = 0.5, and Φ = 2, and use equation (3) to determine MW = ML from Mo. Those for small circular shear fractures (prediction S1; based on equation (A45)) assume S = SC = 4 MPa and m = 2 (so B = 0.7); those for small circular tensile fractures (equation (A49)) assume P = ST = 2 MPa and m = 2 (so B = 0.7; prediction S2) or m = 4 (so B = 1.4; prediction S3). Those for large, square (i.e. L = H), vertical tensile fractures assume K = Pa m−1 and m = 4 (so B = 1.4); they utilize equation (A34) to determine Mo from H, then equation (A54) to determine PGV (prediction S4). Other estimates of the magnitudes of ‘nuisance’ vibrations correspond to those depicted; thus, for example (Table 1), PGV may reach 12.7 mm s−1 from a slamming door (Stagg et al. 1980) or 2 mm s−1 from a lorry at a distance of c. 8 m (NCHRP 1999).
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors

4. Predictions of magnitude thresholds for a given PGV at a given epicentral distance from an earthquake source of a given magnitude, calculated, using the same procedures and parameter values as for Figure 1, for the limits for PGV at different times of day that are recommended by BS
Predictions of magnitude thresholds for a given PGV at a given epicentral distance from an earthquake source of a given magnitude, calculated, using the same procedures and parameter values as for Figure 1, for the limits for PGV at different times of day that are recommended by BS (a) Shear fracture earthquakes with B = 0.7; (b) tensile fracture earthquakes with B = 0.7; (c) tensile fracture earthquakes with B = 1.4.
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors

5. (a) Graphs illustrating the variations with ν of P-wave and S-wave corner frequencies for tensile earthquakes, plotted as fcTP × 2πa/vs and fcTS × 2πa/vs, for different values of ζT, calculated as explained in the text.
(a) Graphs illustrating the variations with ν of P-wave and S-wave corner frequencies for tensile earthquakes, plotted as fcTP × 2πa/vs and fcTS × 2πa/vs, for different values of ζT, calculated as explained in the text. (b) Equivalent graphs illustrating the variations in P-wave and S-wave corner frequencies for shear earthquakes, plotted as fcSP × 2πa/vs and fcSS × 2πa/vs, for different values of ζS. The graphs for ζT or ζS = b and ζT or ζS = 1.4 converge as ν → 0 because b → 1.4 as ν → 0, b being √2 or c when ν = 0.
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors

6. Effects of raypath inclination, θ, on predictions of peak ground velocity for tensile earthquakes on vertical fractures.
Effects of raypath inclination, θ, on predictions of peak ground velocity for tensile earthquakes on vertical fractures. (a) Graph of RTPS ≡ vmaxTP/vmaxTS for ν = 0.18 (for which b ≈ 1.60 and λ/μ = ), using equations (A57) and (A58), for the specified values of ζT. (b) Graphs of vmaxTP and vmaxTS in relative units (for C/z = 1), using equations (A57) and (A58) again with ν = 0.18, for different values of ζT. (c) Graphs of vmaxTP and vmaxTS, likewise in relative units and based on equations (A57) and (A58), for ζT = b and different values of ν.
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors

7. Graphs of RTSSS as a function of ν and ζ for the case where P/S = 0
Graphs of RTSSS as a function of ν and ζ for the case where P/S = 0.5 (a) Comparison of tensile and shear earthquakes with the same source radius, based on equation (A64).
Graphs of RTSSS as a function of ν and ζ for the case where P/S = 0.5 (a) Comparison of tensile and shear earthquakes with the same source radius, based on equation (A64). (b) Comparison of tensile and shear earthquakes with the same seismic moment, based on equation (A65).
Rob Westaway, and Paul L. Younger Quarterly Journal of Engineering Geology and Hydrogeology 2014;47:
© 2014 The Authors