Advanced seismic microzoning of the complex sedimentary basin of Martgny (Switzerland) by two-dimensional Aki-Larner method and three-dimentional spectral-element method.

Florent De Martin 1, * Corinne Lacave 2 Emmanuel Chaljub 3 Jean-Daniel Rouiller 4
* Auteur correspondant
1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 Résonance Ingénieurs-Conseil SA
3 ISTerre - Institut des Sciences de la Terre
4 Centre de Recherches sur l?Environnement Alpin
Abstract : The region of Martigny (Valais, Switzerland) is located at the confluence of two ancient Alpine glaciers: the Rhone and Dranse glaciers. Such a confluence had for consequence the creation of adeep, steep-sided and complex three-dimensional (3D) valley reaching 1 km depth and spreading 3 km wide (at maximum, see Figure 1). The valley is filled with quaternary sediment formations whose shear-wave velocity structure has been determined by geophysical campaigns performed duringformer projects (e.g., geothermal prospection): the shear-wave velocities range from 250 m/s at the shallowest formation to 1350 m/s at 1 km depth.The underlying seismological bedrock'sshear-wave velocity has been approximated to 3000 m/s.In order to determine elastic response spectra for the future seismic microzoning of the region, the " Centre de Recherche sur l'Environnement Alpin " (CREALP) mandated three institutes to perform two-and three-dimensional advanced numerical seismic wave propagations toquantify the complex basin's seismic response and its associated uncertainties.This presentation aims at showing: i) the semi-automatic meshing/refiningtechnique developed for arbitrary3D sedimentary basin surrounded by steep topography, ii) the medium homogenization technique to include arbitrary 2D sediment/bedrock interface in a 3D finite-element mesh and iii) the results obtained by a 2D Aki-Larner method code and two spectral-element method codes (SPECFEM3D and EFISPEC3D). Figure 1: 3D view of the deep steep-sided basin of the region of Martigny.
Type de document :
Communication dans un congrès
Workshop Numerical Modeling of Earthquake Motions: Waves and Ruptures, Jul 2015, Bratislava, Slovakia
Liste complète des métadonnées
https://hal-brgm.archives-ouvertes.fr/hal-01142180
Contributeur : Florent De Martin <>
Soumis le : mardi 14 avril 2015 - 16:23:54
Dernière modification le : mardi 29 mai 2018 - 12:51:02
Document(s) archivé(s) le : lundi 14 septembre 2015 - 08:37:12

Fichiers

NMEM2015_DeMartin_etal.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

  • HAL Id : hal-01142180, version 1

Collections

BRGM | UNIV-SAVOIE | OSUG | INSU | UGA | IFSTTAR | IRD | ISTERRE | TDS-MACS

Citation

Florent De Martin, Corinne Lacave, Emmanuel Chaljub, Jean-Daniel Rouiller. Advanced seismic microzoning of the complex sedimentary basin of Martgny (Switzerland) by two-dimensional Aki-Larner method and three-dimentional spectral-element method.. Workshop Numerical Modeling of Earthquake Motions: Waves and Ruptures, Jul 2015, Bratislava, Slovakia. 〈hal-01142180〉

Exporter

BibTeX TEI DC DCterms EndNote

Partager

Métriques

Consultations de la notice

333

Téléchargements de fichiers

97

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD