PSHA after a strong earthquake: hints for the recovery

L. Peruzza (1) , R. Gee (2) , B. Pace , G. Roberts (3) , O. Scotti (4) , F. Visini , L Benedetti (5) , M. Pagani

1 Centro Ricerche Sismologiche Borgo Grotta Gigante
2 OGS - National Institute of Oceanography and Experimental Geophysics
3 CNRM - Centre national de recherches météorologiques
4 IRSN/PSE-ENV/SCAN/BERSSIN - Bureau d'évaluation des risques sismiques pour la sûreté des installations
5 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement

We perform aftershock probabilistic seismic hazard analysis (APSHA) of the ongoing aftershock sequence following the Amatrice August 24th, 2016 Central Italy earthquake. APSHA is a time-dependent PSHA calculation where earthquake occurrence rates decrease after the occurrence of a mainshock following an Omori-type decay. In this paper we propose a fault source model based on preliminary evidence of the complex fault geometry associated with the mainshock. We then explore the possibility that the aftershock seismicity is distributed either uniformly or non-uniformly across the fault source. The hazard results are then computed for short-intermediate exposure periods (1-3 months, 1 year). They are compared to the background hazard and intended to be useful for post-earthquake safety evaluation.

Domaines: Sciences de la Terre

L. Peruzza, R. Gee, B. Pace, G. Roberts, O. Scotti, et al.. PSHA after a strong earthquake: hints for the recovery. Annals of Geophysics, 2016, 59 (5), ⟨10.4401/ag-7257⟩. ⟨hal-01758952⟩