Earthquake Ground-Motion Prediction Equations for Eastern North America

Abstract

New earthquake ground-motion relations for hard-rock and soil sites in eastern North America (ENA), including estimates of their aleatory uncertainty (variability) have been developed based on a stochastic finite-fault model. The model incorporates new information obtained from ENA seismographic data gathered over the past 10 years, including three-component broadband data that provide new information on ENA source and path effects. Our new prediction equations are similar to the previous ground-motion prediction equations of Atkinson and Boore (1995), which were based on a stochastic point-source model. The main difference is that high-frequency amplitudes (f Ն 5 Hz) are less than previously predicted (by about a factor of 1.6 within 100 km), because of a slightly lower average stress parameter (140 bars versus 180 bars) and a steeper near-source attenuation. At frequencies less than 5 Hz, the predicted ground motions from the new equations are generally within 25% of those predicted by Atkinson and Boore (1995). The prediction equations agree well with available ENA ground-motion data as evidenced by near-zero average residuals (within a factor of 1.2) for all frequencies, and the lack of any significant residual trends with distance. However, there is a tendency to positive residuals for moderate events at high frequencies in the distance range from 30 to 100 km (by as much as a factor of 2). This indicates epistemic uncertainty in the prediction model. The positive residuals for moderate events at Ͻ100 km could be eliminated by an increased stress parameter, at the cost of producing negative residuals in other magnitude-distance ranges; adjustment factors to the equations are provided that may be used to model this effect.Online material: Database of response spectra for hard-rock sites in ENA.

A κ Model for Mainland France

“…COTTON et al, 2006); (2) develop simulation-based GMPEs using input parameters derived from seismological analyses, as, for example, have been developed for eastern North America (e.g. ATKINSON and BOORE, 2006); or (3) adjust GMPEs developed for other regions to be more applicable to France through, for example, the hybrid empirical-stochastic technique (e.g. CAMPBELL, 2003;DOUGLAS et al, 2006) or the referenced empirical approach (ATKINSON, 2008).…”

Comment on Sousa, M. L. and Costa, A. C., “Ground motion scenarios consistent with probabilistic seismic hazard disaggregation analysis. Application to Mainland Portugal”

“…For comparison, the Atkinson and Boore (2006) stochastic ground motion relations for Eastern North America-a well documented case of low attenuationpredict in these conditions a peak ground acceleration (PGA) of 0.35m/s 2 , more consistent with intensity 5-6 (Atkinson and Kaka 2007). Observed MMI intensities for Lisbon are around 9 (Vilanova et al 2003).…”

Earthquake Magnitude and Shaking Intensity Dependent Fragility Functions for Rapid Risk Assessment of Buildings

“…The generated vulnerability functions were then tabulated in a database giving performance points, respective probabilistic damage states and associated IMs. The complete database includes three tables created for different GMPEs, two for Eastern North America (ENA) and one for Western North America (WNA) [12][13][14], for a total of 38,400 tests or ≈2 million vulnerability results. Once developed, the database of damage state probabilities conditioned to the input IMs could readily be used for assessing the expected building damage and corresponding economic and social losses for any potential level of seismic shaking (magnitude-distance-site condition scenarios).…”