Identifying SS reflections in conventional onshore multicomponent data

2021 ◽  
Author(s):  
Saul E. Guevara ◽  
Daniel O. Trad
Keyword(s):  
Multicomponent Data

3D passive wavefield imaging using the energy norm

Geophysics ◽  
2019 ◽  
Vol 84 (2) ◽  
pp. KS13-KS27 ◽  
Author(s):  
Daniel Rocha ◽  
Paul Sava ◽  
Jeffrey Shragge ◽  
Ben Witten
Keyword(s):  
Wave Mode ◽  
Source Location ◽  
Time Step ◽  
Elastic Wave Equation ◽  
Imaging Condition ◽  
Mode Decomposition ◽  
Passive Seismic ◽  
Anisotropic Elastic ◽  
Wavefield Extrapolation ◽  
Multicomponent Data

In passive seismic monitoring of microseismicity, full-wavefield imaging offers a robust approach for the estimation of source location and mechanism. With multicomponent data and the full 3D anisotropic elastic wave equation, the coexistence of P- and S-modes at the source location in time-reversal wavefield extrapolation allows the development of imaging conditions that identify the source position and radiation pattern. We have developed an imaging condition for passive wavefield imaging that is based on energy conservation and is related to the source mechanism. Similar to the correlation between the decomposed P- and S-wavefields — the most common imaging condition used in passive elastic wavefield imaging — our proposed imaging condition compares the different modes present in the displacement field producing a strong and focused correlation at the source location without costly wave-mode decomposition at each time step. Numerical experiments demonstrate the advantages of the proposed imaging condition (compared to PS correlation with decomposed wave modes), its sensitivity with respect to velocity inaccuracy, and its quality and efficacy in estimating the source location.

scholarly journals On the Marchenko equation for multicomponent single-sided reflection data

2014 ◽  
Vol 199 (3) ◽  
pp. 1367-1371 ◽  
Author(s):  
Kees Wapenaar ◽  
Evert Slob
Keyword(s):  
Green’S Function ◽  
Recent Work ◽  
Green's Function ◽  
Scattered Field ◽  
Iterative Solution ◽  
Virtual Source ◽  
Function Representation ◽  
Reflection Data ◽  
Marchenko Equation ◽  
Multicomponent Data

Abstract Recent work on the Marchenko equation has shown that the scalar 3-D Green's function for a virtual source in the subsurface can be retrieved from the single-sided reflection response at the surface and an estimate of the direct arrival. Here, we discuss the first steps towards extending this result to multicomponent data. After introducing a unified multicomponent 3-D Green's function representation, we analyse its 1-D version for elastodynamic waves in more detail. It follows that the main additional requirement is that the multicomponent direct arrival, needed to initiate the iterative solution of the Marchenko equation, includes the forward-scattered field. Under this and other conditions, the multicomponent Green's function can be retrieved from single-sided reflection data, and this is demonstrated with a 1-D numerical example.

Joint PP and PS Stratigraphic Inversion for Prestack Time Migrated Multicomponent Data

2005 ◽  
Author(s):  
D. Mace ◽  
Y. Agullo ◽  
K. Labat ◽  
T. Tonellot ◽  
A. Bourgeois ◽  
...  
Keyword(s):  
Multicomponent Data

Continuous Progress in Processing Multicomponent Data - a Case Study

2002 ◽  
Author(s):  
B. Olofsson ◽  
J.H. Kommedal ◽  
O.I. Barkved ◽  
R. Alexandre ◽  
J. Brunelliere ◽  
...  
Keyword(s):  
Continuous Progress ◽  
Multicomponent Data

EXTRACTING SUB-SURFACE INFORMATION FROM LONG OFFSET P-WAVE DATA—A CHEAPER ALTERNATIVE TO MULTICOMPONENT OBC FOR EXPLORATION?

2002 ◽  
Vol 42 (1) ◽  
pp. 627
Author(s):  
R.G. Williams ◽  
G. Roberts ◽  
K. Hawkins
Keyword(s):  
Seismic Energy ◽  
Higher Order ◽  
P Wave ◽  
S Wave ◽  
Additional Information ◽  
Wave Data ◽  
Wave Velocities ◽  
Avo Inversion ◽  
Long Offset ◽  
Multicomponent Data

Seismic energy that has been mode converted from pwave to s-wave in the sub-surface may be recorded by multi-component surveys to obtain information about the elastic properties of the earth. Since the energy converted to s-wave is missing from the p-wave an alternative to recording OBC multi-component data is to examine p-wave data for the missing energy. Since pwave velocities are generally faster than s-wave velocities, then for a given reflection point the converted s-wave signal reaches the surface at a shorter offset than the equivalent p-wave information. Thus, it is necessary to record longer offsets for p-wave data than for multicomponent data in order to measure the same information.A non-linear, wide-angle (including post critical) AVO inversion has been developed that allows relative changes in p-wave velocities, s-wave velocities and density to be extracted from long offset p-wave data. To extract amplitudes at long offsets for this inversion it is necessary to image the data correctly, including correcting for higher order moveout and possibly anisotropy if it is present.The higher order moveout may itself be inverted to yield additional information about the anisotropy of the sub-surface.

Estimation of horizontal-to-vertical spectral ratios (ellipticity) of Rayleigh waves from multistation active-seismic records

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. EN81-EN92 ◽  
Author(s):  
Binbin Mi ◽  
Yue Hu ◽  
Jianghai Xia ◽  
Laura Valentina Socco
Keyword(s):  
Rayleigh Wave ◽  
Rayleigh Waves ◽  
Spectral Ratio ◽  
Lateral Velocity ◽  
Mode Separation ◽  
Novel Approach ◽  
Single Station ◽  
Seismic Records ◽  
Hvsr Technique ◽  
Multicomponent Data

The horizontal-to-vertical spectral-ratio (HVSR) analysis of ambient noise recordings is a popular reconnaissance tool used worldwide for seismic microzonation and earthquake site characterization. We have expanded this single-station passive HVSR technique to active multicomponent data. We focus on the calculation of the HVSR of Rayleigh waves from active-seismic records. We separate different modes of Rayleigh waves in seismic dispersion spectra and then estimate the HVSR for the fundamental mode. The mode separation is implemented in the frequency-phase velocity ([Formula: see text]-[Formula: see text]) domain through the high-resolution linear Radon transformation. The estimated Rayleigh-wave HVSR curve after mode separation is consistent with the theoretical HVSR curve, which is computed by solving the Rayleigh-wave eigenproblem in the laterally homogeneous layered medium. We find that the HVSR peak and trough frequencies are very sensitive to velocity contrast and interface depth and that HVSR curves contain information on lateral velocity variations. Using synthetic and field data, we determine the validity of estimating active Rayleigh-wave HVSR after mode separation. Our approach can be a viable and more accurate alternative to the empirical HVSR analysis method and brings a novel approach for the analysis of active multicomponent seismic data.

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