Rayleigh-wave tomography at Coronation Field, Canada: The topography effect

Haney, Matthew M.; Douma, Huub

doi:10.1190/1.3679328

Cited by 18 publications

(13 citation statements)

References 11 publications

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“…Although the result with the NGES data set is promising, more testing of the Dix-type relation with near-surface data sets is necessary to establish its effectiveness. Of particular interest is the use of the surface-wave Dix-type relation to process ground roll in exploration seismic surveys for obtaining near-surface shear wave velocities (Haney and Douma, 2012;Douma and Haney, 2013). At the continental scale, we also plan to apply the underparameterized method for large-scale mapping of the Moho in regions with existing surface-wave phase velocity maps.…”

Section: Discussionmentioning

confidence: 99%

Nonperturbational surface-wave inversion: A Dix-type relation for surface waves

Haney

Tsai

2015

GEOPHYSICS

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We extend the approach underlying the well-known Dix equation in reflection seismology to surface waves. Within the context of surface wave inversion, the Dix-type relation we derive for surface waves allows accurate depth profiles of shear-wave velocity to be constructed directly from phase velocity data, in contrast to perturbational methods. The depth profiles can subsequently be used as an initial model for nonlinear inversion. We provide examples of the Dix-type relation for under-parameterized and over-parameterized cases. In the under-parameterized case, we use the theory to estimate crustal thickness, crustal shear-wave velocity, and mantle shear-wave velocity across the Western U.S. from phase velocity maps measured at 8-, 20-, and 40-s periods. By adopting a thin-layer formalism and an over-parameterized model, we show how a regularized inversion based on the Dix-type relation yields smooth depth profiles of shearwave velocity. In the process, we quantitatively demonstrate the depth sensitivity of surface-wave phase velocity as a function of frequency and the accuracy of the Dix-type relation. We apply the over-parameterized approach to a nearsurface data set within the frequency band from 5 to 40 Hz and find overall agreement between the inverted model and the result of full nonlinear inversion.

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Section: Discussionmentioning

confidence: 99%

Nonperturbational surface-wave inversion: A Dix-type relation for surface waves

Haney

Tsai

2015

GEOPHYSICS

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“…) in order to control the lateral coherence of mode identification (Strobbia et al . ; Haney and Douma ; Boiero et al . a; Ezersky et al .…”

Section: Surface‐wave Profilingmentioning

confidence: 99%

2D characterization of near‐surface : surface‐wave dispersion inversion versus refraction tomography

Pasquet

Bodet

Longuevergne

et al. 2015

Near Surface Geophysics

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International audienceThe joint study of pressure (P-) and shear (S-) wave velocities (Vp and Vs ), as well as their ratio (Vp /Vs), has been used for many years at large scales but remains marginal in near-surface applications. For these applications, and are generally retrieved with seismic refraction tomography combining P and SH (shear-horizontal) waves, thus requiring two separate acquisitions. Surface-wave prospecting methods are proposed here as an alternative to SH-wave tomography in order to retrieve pseudo-2D Vs sections from typical P-wave shot gathers and assess the applicability of combined P-wave refraction tomography and surface-wave dispersion analysis to estimate Vp/Vs ratio. We carried out a simultaneous P- and surface-wave survey on a well-characterized granite-micaschists contact at Ploemeur hydrological observatory (France), supplemented with an SH-wave acquisition along the same line in order to compare Vs results obtained from SH-wave refraction tomography and surface-wave profiling. Travel-time tomography was performed with P- and SH- wave first arrivals observed along the line to retrieve Vtomo p and Vtomo s models. Windowing and stacking techniques were then used to extract evenly spaced dispersion data from P-wave shot gathers along the line. Successive 1D Monte Carlo inversions of these dispersion data were performed using fixed Vp values extracted from Vtomo p the model and no lateral constraints between two adjacent 1D inversions. The resulting 1D Vsw s models were then assembled to create a pseudo-2D Vsw s section, which appears to be correctly matching the general features observed on the section. If the pseudo-section is characterized by strong velocity incertainties in the deepest layers, it provides a more detailed description of the lateral variations in the shallow layers. Theoretical dispersion curves were also computed along the line with both and models. While the dispersion curves computed from models provide results consistent with the coherent maxima observed on dispersion images, dispersion curves computed from models are generally not fitting the observed propagation modes at low frequency. Surface-wave analysis could therefore improve models both in terms of reliability and ability to describe lateral variations. Finally, we were able to compute / sections from both and models. The two sections present similar features, but the section obtained from shows a higher lateral resolution and is consistent with the features observed on electrical resistivity tomography, thus validating our approach for retrieving Vp/Vs ratio from combined P-wave tomography and surface-wave profiling

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“…Note that the use of dense single sensors in land acquisition allows the near surface velocity to be accurately estimated; for example, Strobbia et al . () and Haney and Douma () illustrate methods that take advantage of well‐sampled receiver arrays to extract surface‐wave propagation velocities.…”

Section: Discussionmentioning

confidence: 99%

Scattered ground‐roll attenuation using model‐driven interferometry

Halliday

Bilsby

West

et al. 2014

Geophysical Prospecting

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Scattered ground roll is a type of noise observed in land seismic data that can be particularly difficult to suppress. Typically, this type of noise cannot be removed using conventional velocity‐based filters. In this paper, we discuss a model‐driven form of seismic interferometry that allows suppression of scattered ground‐roll noise in land seismic data. The conventional cross‐correlate and stack interferometry approach results in scattered noise estimates between two receiver locations (i.e. as if one of the receivers had been replaced by a source). For noise suppression, this requires that each source we wish to attenuate the noise from is co‐located with a receiver. The model‐driven form differs, as the use of a simple model in place of one of the inputs for interferometry allows the scattered noise estimate to be made between a source and a receiver. This allows the method to be more flexible, as co‐location of sources and receivers is not required, and the method can be applied to data sets with a variety of different acquisition geometries. A simple plane‐wave model is used, allowing the method to remain relatively data driven, with weighting factors for the plane waves determined using a least‐squares solution. Using a number of both synthetic and real two‐dimensional (2D) and three‐dimensional (3D) land seismic data sets, we show that this model‐driven approach provides effective results, allowing suppression of scattered ground‐roll noise without having an adverse effect on the underlying signal.

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Rayleigh-wave tomography at Coronation Field, Canada: The topography effect

Cited by 18 publications

References 11 publications

Nonperturbational surface-wave inversion: A Dix-type relation for surface waves

Nonperturbational surface-wave inversion: A Dix-type relation for surface waves

2D characterization of near‐surface : surface‐wave dispersion inversion versus refraction tomography

Scattered ground‐roll attenuation using model‐driven interferometry

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