NGA-West2 Equations for Predicting PGA, PGV, and 5% Damped PSA for Shallow Crustal Earthquakes

Abstract

We provide ground motion prediction equations for computing medians and standard deviations of average horizontal component intensity measures (IMs) for shallow crustal earthquakes in active tectonic regions. The equations were derived from a global database with M 3.0–7.9 events. We derived equations for the primary M- and distance-dependence of the IMs after fixing the V S30-based nonlinear site term from a parallel NGA-West2 study. We then evaluated additional effects using mixed effects residuals analysis, which revealed no trends with source depth over the M range of interest, indistinct Class 1 and 2 event IMs, and basin depth effects that increase and decrease long-period IMs for depths larger and smaller, respectively, than means from regional V S30-depth relations. Our aleatory variability model captures decreasing between-event variability with M, as well as within-event variability that increases or decreases with M depending on period, increases with distance, and decreases for soft sites.

Between-event and between-station variability observed in the Fourier and response spectra domains: comparison with seismological models

“…For example, Youngs et al (1995) suggested the reduction of the stress drop variability with increasing magnitude as a possible explanation for the reduction of the PGA between-event variability with increasing magnitude. The variability of σ for small magnitude earthquakes has been also mentioned by Boore et al (2014) as one of the possible causes for the bump shown by the standard deviation τ around 0.08 s. Bindi et al (2007) highlighted a clear dependence of δB e on σ for the aftershocks of the 1999 Izmit sequence (Turkey). The connection between σ estimated from spectral analysis (i.e.…”

New predictive equations and site amplification estimates for the next-generation Swiss ShakeMaps

“…Indeed, a slight oversaturation (e.g. Boore et al 2014;Cauzzi et al 2014) of near-source PGA values can be observed for M W > 6.…”

Peak ground accelerations from large (M ≥ 7.2) shallow crustal earthquakes: a comparison with predictions from eight recent ground-motion models

“…The observations are compared to predictions from eight recent GMPEs that are not excluded by the criteria of Bommer et al (2010): Abrahamson et al (2014), Akkar et al (2014b, c), Bindi et al (2014a, b), Boore et al (2014), Campbell and Bozorgnia (2014), Cauzzi et al (2015), Chiou and Youngs (2014) and Zhao et al (2016). Only ground-motion models for shallow crustal earthquakes in active tectonic regimes are considered as almost all identified records come from such regions (as opposed to stable areas).…”

“…2 Magnitude-distance-mechanism distribution of collated data (unfilled symbols indicate data not from the NGA-West2 database). Note that recordings at R JB \ 0.1 km have been plotted at 0.1 km limits proposed by Boore et al (2014, their Fig. 1) for analogue instruments (220 km for M C 7) were considered along with using all data regardless of the distance at which it was recorded, although this is often far beyond the stated range of applicability of the GMPEs.…”

“…Only ground-motion models for shallow crustal earthquakes in active tectonic regimes are considered as almost all identified records come from such regions (as opposed to stable areas). The four NGAWest2 models selected (Abrahamson et al 2014;Boore et al 2014;Campbell and Bozorgnia 2014;Chiou and Youngs 2014) are derived using predominately data from California when considering all magnitudes. For M C 7.2, however, the 1999 Chi-Chi and …”