Record details

    Stability of source mechanisms inverted from P-wave amplitude microseismic monitoring data acquired at the surface
    Eisner, Leo
    Moser, T.J.
    Staněk, František
Publication type
    článek v odborném periodiku
Source title - serial
    Geophysical Prospecting
    Roč. 62, č. 3
    s. 475-490
    Projekt: GAP210/12/2451, GA ČR3cav_un_auth*0284895
    Rozsah: 16 s. : P
Subject category
    microseismic monitoring
    ray modelling
    source mechanism
Abstract (in english)
   We study the stability of source mechanisms inverted from data acquired at surface and near-surface monitoring arrays. The study is focused on P-wave data acquired on vertical components, as this is the most common type of acquisition. We apply ray modelling on three models: a fully homogeneous isotropic model, a laterally homogeneous isotropic model and a laterally homogeneous anisotropic model to simulate three commonly used models in inversion. We use geometries of real arrays, one consisting in surface receivers and one consisting in 'buried' geophones at the near-surface. Stability was tested for two of the frequently observed source mechanisms: strike-slip and dip-slip and was evaluated by comparing the parameters of correct and inverted mechanisms. We assume these double-couple source mechanisms and use quantitatively the inversion allowing non-double-couple components to measure stability of the inversion.
   To test the robustness we inverted synthetic amplitudes computed for a laterally homogeneous isotropic model and contaminated with noise using a fully homogeneous model in the inversion. Analogously amplitudes computed in a laterally homogeneous anisotropic model were inverted in all three models. We show that a star-like surface acquisition array provides very stable inversion up to a very high level of noise in data. Furthermore, we reveal that strike-slip inversion is more stable than dip-slip inversion for the receiver geometries considered here. We show that noise and an incorrect velocity model may result in narrow bands of source mechanisms in Hudson's plots.
    AV ČR Brno, Ústav struktury minerálů a hornin
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Import date
    24. 10. 2014