Publication Date:
2017-04-04
Description:
Macroseismic intensity has recently attracted attention as a tool for validating
probabilistic seismic hazard assessment (PSHA) studies or as an alternative
method for PSHA in countries where the historical catalog is much longer than
the instrumental one. In Italy, the new seismic hazard map was recently produced
using the Cornell–McGuire approach in terms of the peak ground acceleration characterized
by a 10% exceedance probability for an exposure time of 50 yr (Amax). We
compare this map with an alternative one, produced using a different approach based
on a nonparametric and zonation-free statistical analysis of local seismic histories. In
this case, results are expressed in terms of the maximum intensity corresponding to an
exceedance probability of not less than 10% for an exposure time of 50 yr (Iref ). In
order to compare the two maps, we selected 1401 control sites, where local seismic
history includes at least 10 intensity values relative to felt effects documented during
past earthquakes. The values of Amax and Iref at these sites have been ranked in the
respective domains. The spatial distribution of rank differences of Amax and Iref values
shows a strong correlation with the seismogenic zoning used in the calculation of
PSHA following the Cornell–McGuire approach. This suggests that the adopted zoning
could be incomplete (some further “hidden” sources may exist) and too rough to
capture actual seismogenic sources. Because more detailed zoning is prevented by the
amount of data available, the results obtained suggest the preference of zonation-free
approaches for seismic hazard assessment in Italy. Furthermore, among the possible
zonation-free approaches, those that offer better exploitation of local information
about the effects of past earthquakes would be preferred.
Description:
Published
Description:
2652–2664
Description:
4.2. TTC - Scenari e mappe di pericolosità sismica
Description:
JCR Journal
Description:
reserved
Keywords:
probabilistic seismic hazard estimates
;
statistical analysis
;
Italy
;
04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
;
05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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