- Ground-motion model is:
where PSA(0.01s) is in m∕s2, a = -6.899, b = 2.569, c = -2.589, τ = 0.099 (inter-event), ϕ = 0.627
(intra-event) and σ = 0.635 (total).
- Use data from seismic network installed to monitor hot-fractured-rock project at Cooper Basin (Habanero
granite reservoir) with induced seismicity. Use records from 2005 stimulation experiment from 8 stations,
all of which are located below surface (depths ≤ 357m except 1 station at 1.8km).
- Convert data from velocity to acceleration by time-domain differentiation. Assume PGA(0.01s) equals
PGA. Instrument bandwidths do not allow PSAs to be reliably computed for < 15Hz. High-cut filter
records with cut-offs based on signal-to-noise ratio. About a third of cut-offs are > 20Hz, which could
affect PGA. However, find results are insensitive to exclusion of these records so use all data.
- Consistently compute Mw.
- Focal depths between 3.9 and 4.5km following rough normal distribution with peak at 4.2km.
- Develop model for comparison with GMPE logic tree developed using models of Douglas et al. (2013), to
compare with stochastic model and to assess σ and single-station σ.
- Original use c (rather than clnrhypo) and drhypo terms but data not sufficient to constrain
them so they are removed.
- Attribute small τ to small variability in stress drops.
- Compute single-station ϕ (ϕSS,S) for 8 stations and mean ϕSS.