Mean and The M–D deaggregation results provide The mean and modal magnitudes and modal the relative contribution to the site hazard distances should be reported for each magnitude of earthquakes of different sizes and at ground motion parameter and level for and distance different distances. From these which the M–D deaggregated hazard distributions, the mean and/or modal results are given. Unless otherwise magnitudes and the mean and/or modal specified in the work plan, these results distances of earthquakes that contribute to should be reported for response spectral the hazard can be determined. frequencies of 1, 2.5, 5 and 10 Hz. Seismic The seismic hazard at a site is a The seismic source deaggregation should source combination of the hazard from individual be reported for ground motion levels deaggregation seismic sources modelled in the corresponding to each ground motion probabilistic seismic hazard analysis. A parameter considered in the probabilistic deaggregation on the of seismic seismic hazard analysis. The sources provides an insight into the deaggregation should be performed for the possible location and type of future mean hazard and presented as a series of earthquake occurrences. seismic hazard curves. Aggregated In a probabilistic seismic hazard analysis, A of aggregated discrete hazard hazard curves thousands to millions of hazard curves curves, each with an assigned probability are generated to account for epistemic should be reported in tabular as uncertainty. For use in certain applications well as graphic format. (e.g. a seismic probabilistic safety assessment), a smaller, more manageable set of curves is required. Aggregation methods are used to combine like curves that preserve the diversity in shape of the original curves as well as the essential properties of the original set (e.g. the mean hazard). Earthquake For the purposes of engineering analysis, The format for presenting earthquake time time histories time histories may be required that are histories will generally be defined in the consistent with the results of the work plan. probabilistic seismic hazard analysis. The criteria for selecting and/or generating a time history may be specified in the work plan. Example criteria include the selection of time histories that are consistent with the mean and modal magnitudes and distances for a specified ground motion or annual frequency of exceedance. Figure 41 in the PSHA Process
Mean and modal magnitude and distance The M–D deaggregation results provide the relative contribution to the site hazard of earthquakes of different sizes and at different distances. From these distributions, the mean and/or modal magnitudes and the mean and/or modal distances of earthquakes that contribute to the hazard can be determined. The mean and modal magnitudes and distances should be reported for each ground motion parameter and level for which the M–D deaggregated hazard results are given. Unless otherwise specified in the work plan, these results should be reported for response spectral frequencies of 1, 2.5, 5 and 10 Hz. Seismic source deaggregation The seismic hazard at a site is a combination of the hazard from individual seismic sources modelled in the probabilistic seismic hazard analysis. A deaggregation on the of seismic sources provides an insight into the possible location and type of future earthquake occurrences. The seismic source deaggregation should be reported for ground motion levels corresponding to each ground motion parameter considered in the probabilistic seismic hazard analysis. The deaggregation should be performed for the mean hazard and presented as a series of seismic hazard curves. Aggregated hazard curves In a probabilistic seismic hazard analysis, thousands to millions of hazard curves are generated to account for epistemic uncertainty. For use in certain applications (e.g. a seismic probabilistic safety assessment), a smaller, more manageable set of curves is required. Aggregation methods are used to combine like curves that preserve the diversity in shape of the original curves as well as the essential properties of the original set (e.g. the mean hazard). A of aggregated discrete hazard curves, each with an assigned probability should be reported in tabular as well as graphic format. Earthquake time histories For the purposes of engineering analysis, time histories may be required that are consistent with the results of the probabilistic seismic hazard analysis. The criteria for selecting and/or generating a time history may be specified in the work plan. Example criteria include the selection of time histories that are consistent with the mean and modal magnitudes and distances for a specified ground motion or annual frequency of exceedance. The format for presenting earthquake time histories will generally be defined in the work plan. Figure 41 in the PSHA Process
CHAPTERS_1-7__15_Dec_2016_ver_507.docx