TY - GEN

T1 - Estimating a continuous P-wave velocity profile with constant squared-slowness gradient models from seismic field data

AU - Ponomarenko, A. V.

AU - Kashtan, B. M.

AU - Troyan, V. N.

AU - Mulder, W. A.

N1 - Publisher Copyright: © (2015) by the European Association of Geoscientists & Engineers (EAGE). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2015

Y1 - 2015

N2 - We inverted seismic field data for a continuous, laterally invariant P-wave velocity profile. Instead of the usual approach that involves horizontal layers with piecewise constant densities and velocities, we consider models of one or two layers with a constant gradient of the squared slowness above a homogeneous halfspace. With a single layer above a halfspace, there are three parameters. With two layers, there are five. We solve the inverse problem by a direct grid search over a wide range of parameters. The results were compared to that of a piecewise-constant multi-layer inversion result. In the single-layer case, either the shallow or the deeper part of the model would match the multi-layer case, depending on which modes of the surface waves were selected. With two layers, a considerably better agreement is obtained over a larger depth range. Our method is limited to cases with a small Vs/Vp-ratio but has only 5 parameters. It could be a useful alternative to piecewise-constant multi-layer inversion, in particular if continuous P-velocity profiles are sought. These are sometimes better suited as a starting model for full waveform inversion than models with many discontinuities.

AB - We inverted seismic field data for a continuous, laterally invariant P-wave velocity profile. Instead of the usual approach that involves horizontal layers with piecewise constant densities and velocities, we consider models of one or two layers with a constant gradient of the squared slowness above a homogeneous halfspace. With a single layer above a halfspace, there are three parameters. With two layers, there are five. We solve the inverse problem by a direct grid search over a wide range of parameters. The results were compared to that of a piecewise-constant multi-layer inversion result. In the single-layer case, either the shallow or the deeper part of the model would match the multi-layer case, depending on which modes of the surface waves were selected. With two layers, a considerably better agreement is obtained over a larger depth range. Our method is limited to cases with a small Vs/Vp-ratio but has only 5 parameters. It could be a useful alternative to piecewise-constant multi-layer inversion, in particular if continuous P-velocity profiles are sought. These are sometimes better suited as a starting model for full waveform inversion than models with many discontinuities.

UR - http://www.scopus.com/inward/record.url?scp=84958058222&partnerID=8YFLogxK

U2 - 10.3997/2214-4609.201413796

DO - 10.3997/2214-4609.201413796

M3 - Conference contribution

SN - 9781510814127

T3 - Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics

SP - 661

EP - 665

BT - Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics

PB - European Association of Geoscientists and Engineers

T2 - 21st European Meeting of Environmental and Engineering Geophysics, Near Surface Geoscience 2015

Y2 - 6 September 2015 through 10 September 2015

ER -