000019695 001__ 19695
000019695 005__ 20170118182332.0
000019695 04107 $$aeng
000019695 046__ $$k2017-01-09
000019695 100__ $$aEdwards, Ben
000019695 24500 $$aSelection of Gmpes for Probabilistic Seismic Hazard Assessment in Areas of Moderate Seismicity and Resulting Epistemic Uncertainties

000019695 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019695 260__ $$b
000019695 506__ $$arestricted
000019695 520__ $$2eng$$aIn 2015, the reference probabilistic seismic hazard maps for Switzerland were updated. In order to cover epistemic uncertainties in ground-motion prediction two major sets of models were implemented: (1) stochastic and (2) empirical-based models. The stochastic models describe the synthetically generated ground-motion predictions specifically derived for Switzerland. Four models were implemented, in the Alpine and Foreland regions, segregating deep (hypocentral depth > 6 km) and shallow seismicity. All models are referenced to a well-defined rock shear-wave velocity profile and kappa0 value. This reference was derived from shear-wave velocity measurements and the assessment of kappa0 at a large number of seismic stations of the Swiss national seismic networks. The stochastic models are consistent with the magnitudes in the earthquake catalogue of Switzerland (ECOS-09), which was also used to derive the earthquake activity rates in the source model for the probabilistic hazard assessment. Geometrical spreading and attenuation were modeled from the observations in the Foreland and the Alpine regions, derived based on earthquake recordings of small events of the seismic networks in Switzerland and neighboring countries. The scaling to larger magnitudes was achieved using macroseismic data of historical events together with their calibrated moment magnitudes, resulting in an additional branch of the logic tree for the epistemic uncertainty on the stress drop. For verification, the stochastic model was successfully tested against European and Japanese strong-motion data. The empirical set of ground-motion models contains four empirical global ground-motion prediction equations (hereinafter GMPEs) extensively tested within other projects (i.e. Pegasos, SHARE). These models, however, had to be adjusted to the Vs-kappa0 conditions at the reference rock in Switzerland. The adjustment functions were obtained based on the ratio of the expected Fourier amplitude spectra at the host region and the target region. The host Vs profile for each empirical GMPE was estimated based on published information, personal communication with the GMPEs’ authors and expert evaluation. The host kappa0 values were obtained from a mixture of direct measurements and Vs30-based estimates. Additionally, the empirical GMPEs were corrected for small magnitude extrapolation using instrumental data. The adjustments and corrections were applied only to the empirical GMPEs and additional epistemic uncertainties due to these corrections were taken into account in the logic tree. The aleatory uncertainty is represented by single-station variability based on two alternative models. Finally, the two sets of ground motion models were combined together in the logic tree structure, by weighting the stochastic set and the empirical models. Here we present results that show the influence of the two sets of models on the resulting seismic hazard, and discuss the possible reason in the resulting epistemic uncertainties.

000019695 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019695 653__ $$aseismic hazard; ground motion prediction equation; epistemic uncertainty; moderate seismicity;

000019695 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019695 720__ $$aEdwards, Ben$$iCauzzi, Carlo$$iDanciu, Laurentiu$$iFäh, Donat
000019695 8560_ $$ffischerc@itam.cas.cz
000019695 8564_ $$s1399211$$uhttps://invenio.itam.cas.cz/record/19695/files/419.pdf$$yOriginal version of the author's contribution as presented on USB, paper 419.
000019695 962__ $$r16048
000019695 980__ $$aPAPER