RIBODETTI , Alessandra

The north Ligurian margin is a complex geological area in many ways. It has witnessed several phases of highly contrasting deformation styles, at both crustal scale and that of shallower cover tectonics, simultaneously or in quick succession, and with significant spatial variability. This complex interplay is mirrored in the resulting intricate...

Ultra-long offset seabed acquisitions implemented with sparse array of ocean bottom nodes (OBN) are emerging as the goto strategy for velocity model building. These stationaryrecording geometries provide the flexibility to record a plethora of wave arrivals and in particular diving waves that undershoot the deepest targeted structures. These...

We revisit the hypocentre-velocity problem, which is of interest in different fields as for example microseismics and seismology. We develop a formulation based on kinematic migration of two picked kinematic attributes in the two dimensional case, the traveltime and the slope (horizontal component of the slowness vector), from which we are able...

We revisit the hypocenter-velocity problem which is of interest in different fields as for example microseismics and seismology. We show how, through a formulation based on kinematic migration focusing using two picked kinematic attributes in the two-dimensions case, the travel time and the slope (horizontal component of the slowness vector),...

The object of this study is to estimate the viscoelastic parameters (compressionnal velocity and the intrinsic attenuation factor Q) of lava samples in acoustic tomography experiments by the use of an asymptotic viscoacoustic diffraction tomography method developped by Ribidetti et al 2000. 2.5 D common offset ultrasonic experiments are...

Tectonic processes that control the transition from poorly consolidated sediment entering the subduction channel (SC) to the seismogenic zone are documented using seismic imaging. We applied pre-stack depth migration and a post-processing sequence to a seismic reflection line acquired across the Ecuador convergent margin to obtain a...

Slope tomography uses traveltimes, source, and receiver slopes of locally coherent events to build subsurface velocity models. Locally coherent events by opposition to continuous reflections are suitable for semiautomatic and dense picking, which is conducive to better resolved tomographic models. These models can be further used as...

A 2D finite-difference, frequency-domain method was developed for modeling viscoacoustic seismic waves in transversely isotropic media with a tilted symmetry axis. The medium is parameterized by the P-wave velocity on the symmetry axis, the density, the attenuation factor, Thomsen's anisotropic parameters delta and epsilon, and the tilt angle....

In civil engineering, one of the crucial problems is the location of buried polyethylene pipes. For this type of material, electromagnetic waves are less suitable than acoustic waves (e.g. the necessity to introduce a metal cable into the pipeline making the method invasive, difficulty in differentiating between a gas pipe and a water pipe). By...

Localization of buried polyethylene pipes is an important issue for network managers. This study focuses on an acoustic method, which consists of vibrating the pipe and observing the signal with a receiver placed on the ground surface. This method provides an estimate of the path of the pipe but gives no information on the depth. We developed a...

A bridge is highlighted between the direct inversion and the indirect inversion. They are based on fundamental different approaches: one is looking after a projection from the data space to the model space while the other one is reducing a misfit between observed data and synthetic data obtained from a given model. However, it is possible to...

International audience

International audience

Earth and Planetary Science Letters, v. 272, n. 1-2, p. 296-308, 2008. http://dx.doi.org/10.1016/j.epsl.2008.04.049

The computational burden of frequency-domain full-waveform inversion (FWI) of wide-aperture fixed-spread data is conventionally reduced by limiting the inversion to a few discrete frequencies. In this framework, frequency-domain seismic modeling is performed efficiently for multiple sources by solving the linear system resulting from the...

Frequency-domain full waveform inversion (FWI) of fixed-spread data can be limited to a few discrete frequencies thanks to the redundant control of frequency and scattering angle on the wavenumber coverage. In this framework, 3D finite-difference frequency-domain seismic modeling can be efficiently performed for multiple sources in the...

Full waveform inversion (FWI) is a high-resolution seismic imaging technique that is based on using the entire content of seismic traces for extracting physical parameters of the medium sampled by seismic waves. The widespread strategy of seismic imaging, the single scattering formulation, at the core of FWI, assumes no prior scale in the model...

International audience

International audience

Extracting detailed earth information from an ensemble of seismic traces is a challenge facing full-waveform inversion. So far, success on synthetic and real data has been accomplished primarily for the twin purposes of complex structural imaging and geologic interpretation. An ongoing issue for the seismic-imaging community, in addition to...

Building high-resolution models of several physical properties of the subsurface by multi-parameter full waveform inversion (FWI) of multi-component data is one of the challenge of seismic imaging for the next decade. The physical properties, which govern propagation of seismic waves in visco-elastic media, are the P and S wavespeeds, density,...

Building high-resolution models of several physical properties of the subsurface by multi-parameter full waveform inversion (FWI) of multi-component data is one of the challenge of seismic imaging for the next decade. The physical properties, which govern propagation of seismic waves in visco-elastic media, are the P and S wavespeeds, density,...

International audience