Seismic tomography using parameter-free Backus–Gilbert inversion - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Geophysical Journal International Année : 2019

Seismic tomography using parameter-free Backus–Gilbert inversion

Christophe Zaroli
  • Fonction : Auteur
  • PersonId : 925912

Résumé

This proof-of-concept study presents a parameter-free, linear Backus–Gilbert inversion scheme, tractable for seismic tomography problems. It leads to efficient computations of unbiased tomographic images, accompanied by meaningful resolution and uncertainty infor- mations. Moreover, as there is no need to parametrize the model space in this parameter-free approach, it enables numerically accurate data sensitivity kernels to be effectively exploited in tomographic inversions. This is a major benefit over discrete tomographic methods, for which data sensitivity kernels are often inaccurate, as they are projected on a given model parametrization prior to be exploited in the inversion, and these parametrizations are usually coarse to limit the number of parameters and keep tractable the problems of model estima- tion and/or appraisal. Therefore, this new tomographic scheme fuels great hopes on better constraining multiscale seismic heterogeneities in the Earth’s interior by exploiting accurate data sensitivity kernels, that is, taking full advantage of known wave-propagation physics, and enabling quantitative appraisals of tomographic features. As a remark, since its computational cost grows as a function of the total number of data squared, it may be better suited to han- dle moderate-size data sets, typically encountered in regional-scale tomography. Theoretical developments are illustrated within a finite-frequency physical framework. A set of 27 070 teleseismic S -wave time residuals is inverted, with focus on imaging and appraising shear- wave velocity anomalies lying in the mantle below Southeast Asia, in the 350–1410 km depth range.
Fichier principal
Vignette du fichier
islandora_86392.pdf (13.95 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-02123945 , version 1 (09-10-2020)

Identifiants

Citer

Christophe Zaroli. Seismic tomography using parameter-free Backus–Gilbert inversion. Geophysical Journal International, 2019, 218 (1), pp.619-630. ⟨10.1093/gji/ggz175⟩. ⟨hal-02123945⟩
27 Consultations
55 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More