MERCERAT , D.

We compare finite-frequency sensitivity kernels computed from ray-theoretical wavefields ("banana-doughnut" kernels) and from full waveform computations (often called "adjoint" kernels) in order to evaluate resolution, accuracy and computational cost. We focus here on body-wave seismic tomography at regional and local scales. Our results show...

We explore the validity of the linear relation between cross-correlation delay times and velocity model perturbations that is required for linearized finite-frequency tomography. We estimate delay times from a large number of 'ground truth' seismograms computed with the spectral element method in 3-D models. We find that the observed...

We evaluated a comprehensive numerical experiment of finite-frequency tomography with ray-based ("banana-doughnut") kernels that tested all aspects of this method, starting from the generation of seismograms in a 3D model, the window selection, and the crosscorrelation with seismograms predicted for a background model, to the final regularized...

Abstract In this article, we propose an interpretation of the propagation velocities of the pulse wave obtained in vertical structures through seismic interferometry by deconvolution. The novelty of this article is to propose a parametric study applied to canonical finite‐element models of fixed‐base buildings from pure‐shear to pure‐bending...

Distributed Acoustic Sensing (DAS) enables the use of existing underwater telecommunication cables as multi-sensor arrays, allowing for detailed study of the seismic wavefield. Since underwater telecommunication cables were not deployed for seismological investigations, the coupling between the cable and the seafloor varies, dramatically...

SUMMARY The elastoplastic Iwan model has been used since the end of the 1970s to simulate nonlinear soil behaviour in seismic wave propagation. In this work, we present an automatic algorithm to efficiently sample the shear-modulus reduction curve in function of shear deformation, which constitutes the exclusive ingredient of the elastoplastic...

SUMMARY We report here an interesting case study of dynamic characterization of a limestone sea cliff area, named the Sutta-Rocca overhang, located near the medieval town of Bonifacio (southern Corsica, France). The site belongs to an UNESCO protected area with an important number of visitors per year. Therefore, it is of particular interest to...

A megathrust subduction earthquake (Mw 7.8) struck the coast of Ecuador on 16 April 2016 at 23:58 UTC. This earthquake is one of the best‐recorded megathrust events to date. Besides the mainshock, two large aftershocks have been recorded on 18 May 2016 at 7:57 (Mw 6.7) and 16:46 (Mw 6.9). These data make a significant contribution for...

The Earth is an heterogeneous complex media from the mineral composition scale (10−6m) to the global scale ( 106m). The reconstruction of its structure is a quite challenging problem because sampling methodologies are mainly indirect as potential methods (Günther et al., 2006; Rücker et al., 2006), diffusive methods (Cognon, 1971; Druskin &...

ABSTRACT The presence of multiscale interactions means that the complex urban wavefield must be observed and analyzed in order to understand seismic ground motion in urban environments. Originally called site–city interaction, the interactions between soil and structures, structures and soil, and between structures contribute to the...

The goal of the work presented in a two-companion paper is to pave the way for reliably assessing the risks of damage to buildings on the shore, induced by the detonation of unexploded historical ordnance (UXO) of large weights in variable shallow water environments with a water depth less than 50 m. The risk assessment is quantified through...

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