Geophysics

    Research activities

    The research activities winth the Geophysical Research Group from MINES ParisTech is organised along three main axis:

    Inversion Velocity Analysis – Stochastic tomography – Geomechanics

    The three axis are complementary. In a more long-term prespective, the stochastic approach is the central part to evaluate reliable uncertainties

    Its main research activities are the development of advanced seismic imaging tools, as well as the link between seismic imaging and geomechacnical modelling. Different scales are considered, from the near subsuface, the exploration scale to the seismological scale.

    Permanent scientific staff

    Hervé Chauris (Head) – Pierre Dublanchet – Alexandrine Gesret – Mark Noble

    Administrative staff

    Véronique Lachasse

    More information on the team:
    Staff
    Publications
    PHD Positions

     

    INVERSION VELOCITY ANALYSIS

    The objective is to derive an initial model for subsequent Full Waveform Inversion. It consists of analysing focusing panels (e.g. Common Image Gathers). For the correct model, different images of the subsurface should be consistent.

    The recent advances are:

    • the derivation and introduction of a direct inverse (instead of the adjoint of the Born modelling operator) for much more macro-model gradients (Chauris and Cocher, 2017);
    • the extension beyond reflected waves, with the incorporation of multiples (Cocher and Chauris, 2017) and transmitted waves (Lameloise and Chauris, 2016.

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    STOCHASTIC TOMOGRAPHY

    In collaboration with the Geostatistics team, we have developed a research activity dedicated to the stochastic geophysics in order to reliably estimate uncertainties associated to the velocity model and to the seismic event locations (Gesret et al., 2015).

    We recently focused on first arrival traveltime tomography with development of:

    efficient algorithms for both the forward problem (Noble et al., 2014) and the inverse problem (Boterro et al., 2016; Luu et al., 2018);

    parsimonious parameterizations of the velocity model (Boterro et al., 2016; Belhadj et al., 2018).

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    GEOMECHANICS

    Our main contributions are the development and the study of mechanical models of frictional faults and frictional fault networks. We use these models to understand seismicity and aseismic deformations in diferent contexts (natural tectonic activity or induced by fluid operations at depth).

    Recent advances concern:

    the understanding of earthquake nucleation on a heterogeneous Dieterich-Ruina rate-and-state frictional fault (Dublanchet, 2018);                                      the understanding of seismic activity induced by a fluid injection into a heterogeneous rate-and-state fault (Almakari et al., 2018).

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    PhD and postdoctoral studies

    PhD students

    Ph Defenses 2019, 2020
                    Sismicité induite dans un modèle de faille rate-and-state Michelle ALMAKARI

    HAL Publications