Assessing the influence of around-source deep crustal heterogeneities on the seismic wave propagation by 3-D broad-band numerical modelling

Martin Colvez , Fernando Lopez‐caballero (1, 2) , F Gatti (2) , Régis Cottereau (2)

1 CentraleSupélec
2 MSSMat - Laboratoire de mécanique des sols, structures et matériaux

Tectonic and seismic activities induce crustal rock fracturing in the immediate surroundings of buried fault discontinuities. The heterogeneous nature of this 3-D scatter distribution leaves a high-frequency footprint on the recorded wave-field at surface. This study represents an attempt to clarify the complex relationship between the propagated wave-field and the statistical properties of the regional medium. This objective is pursued by inspecting the broadband (0-25Hz) synthetic wave-forms obtained by sourceto-site 3-D numerical simulations in regional-size scenarios. The presented numerical study compares the major differences obtained when including heterogeneous properties in the model. Coda-waves are analysed and the high-frequency attenuation is assessed by computing the κ coefficient for different source-station configurations.

Domaines: Risques; Dynamique, vibrations

Martin Colvez, Fernando Lopez‐caballero, F Gatti, Régis Cottereau. Assessing the influence of around-source deep crustal heterogeneities on the seismic wave propagation by 3-D broad-band numerical modelling. 13th International Conference on Applications of Statistics and Probability in Civil Engineering(ICASP13), May 2019, Seoul, South Korea. ⟨hal-02142977⟩