Dear Nitin,
The mean hazard curves obtained from the EFEHR () portal represent the weighted(arithmetic) mean.
Each hazard curve resulted as an aggregation of thee independent source models:
- area source model (As Model)
- faults + background source model (fsFb Model)
- smoothed seismicity (SEIFA Model)
The computation was performed per tectonic regions (i.e. Active Shallow Crust, Oceanic Crust, Stable Continental, Shield, Volcanic, Subduction Inslab, Subduction Interface, Deep Seismicity -Vrancea Region ); where each GMPE of the corresponding ground motion logic tree represents and individual end-branch.
These
individual end-branches were summed up to form the
tectonic-mean hazard curves, in turn these tectonic-mean hazard curves were summed up to generate the
source mean-hazard curves; finally the three source mean-hazard curves were weighted to generate the
final mean model (available online at
efehr.org) The hazard curve aggregation was done by operating on the exceedance rates rather then probabilities. This is different than the OQ mean hazard curves, that is based on probabilities summation.
Also, if you want to replicate the calculation, you need to represent each source model into individual tectonic source models. Depending on your hardware capability you might want to try a single site computation with the entire SHARE source model. If you use this option make sure, you consider the appropriate option of the
new configuration setting of OQ (ver1.0 and above)
individual_curves = false
If this is set to false, OQ will not output the individual end-branches results. This option was not implemented at the time of the SHARE computation (Spring 2013).
I hope this helps, Cheers Laurentiu