scholarly journals Determination of Phase-Velocity Dispersion Curves of Rayleigh Surface Waves from Tidal Gravimetric Recordings of Earthquakes

2021 ◽  
Author(s):  
Monika Wilde-Piórko ◽  
Kamila Karkowska
Keyword(s):  
Phase Velocity ◽  
Surface Waves ◽  
Velocity Dispersion ◽  
Dispersion Curves ◽  
Rayleigh Surface Waves ◽  
Phase Velocity Dispersion

New techniques for the determination of surface wave phase velocities

1968 ◽  
Vol 58 (3) ◽  
pp. 1021-1034 ◽  
Author(s):  
S. Bloch ◽  
A. L. Hales
Keyword(s):  
Phase Velocity ◽  
Rayleigh Waves ◽  
World Wide ◽  
Velocity Dispersion ◽  
Cross Product ◽  
New Techniques ◽  
Phase Velocities ◽  
Phase Velocity Dispersion ◽  
The World

abstract A number of new techniques have been developed for the determination of phase velocities from the digitized seismograms from pairs of stations. One of these techniques is to Fourier analyze the sum (or difference) of the two seismograms after time shifting in steps to correspond to steps in phase velocity. The amplitude of the summed seismogram is a maximum for any particular period when both seismograms are in phase at that period. Another method is to pass both seismograms through a narrow bandpass digital filter centered at various periods and form the cross product of the filtered seismograms, after time shifting. The average of the resultant time series is a maximum when the two signals are in phase. The computer output is a matrix consisting of amplitudes or averages as a function of phase velocity and period. The phase velocity dispersion is determined from the contoured matrix. Using these techniques, interstation phase velocities of Rayleigh waves have been determined for the “World Wide Network Standard Stations” at Pretoria, Bulawayo and Windhoek. The method using cross-products is the most efficient.

Combining surface-wave phase-velocity dispersion curves and full microtremor horizontal-to-vertical spectral ratio for subsurface sedimentary site characterization

2016 ◽  
Vol 4 (4) ◽  
pp. SQ41-SQ49 ◽  
Author(s):  
Agostiny Marrios Lontsi ◽  
Matthias Ohrnberger ◽  
Frank Krüger ◽  
Francisco José Sánchez-Sesma
Keyword(s):  
Surface Wave ◽  
Phase Velocity ◽  
Velocity Dispersion ◽  
Spectral Ratio ◽  
Test Site ◽  
Dispersion Curves ◽  
Surface Velocity ◽  
Wave Phase ◽  
Phase Velocity Dispersion ◽  
Wave Phase Velocity

We compute seismic velocity profiles by a combined inversion of surface-wave phase-velocity dispersion curves together with the full spectrum of the microtremor horizontal-to-vertical (H/V) spectral ratio at two sediment-covered sites in Germany. The sediment deposits are approximately 100 m thick at the first test site and approximately 400 m thick at the second test site. We have used an extended physical model based on the diffuse wavefield assumption for the interpretation of the observed microtremor H/V spectral ratio. The extension includes the interpretation of the microtremor H/V spectral ratio observed at depth (in boreholes). This full-wavefield approach accounts for the energy contribution from the body and surface waves, and thus it allows for inverting the properties of the shallow subsurface. We have obtained the multimode phase velocity dispersion curves from an independent study, and a description of the extracted branches and their interpretation was developed. The inversion results indicate that the combined approach using seismic ambient noise and actively generated surface-wave data will improve the accuracy of the reconstructed near-surface velocity model, a key step in microzonation, geotechnical engineering, seismic statics corrections, and reservoir imaging.

scholarly journals Repulsion of phase‐velocity dispersion curves and the nature of plate vibrations

1994 ◽  
Vol 96 (2) ◽  
pp. 908-917 ◽  
Author(s):  
H. Überall ◽  
B. Hosten ◽  
M. Deschamps ◽  
A. Gérard
Keyword(s):  
Phase Velocity ◽  
Velocity Dispersion ◽  
Dispersion Curves ◽  
Plate Vibrations ◽  
Phase Velocity Dispersion

scholarly journals A Robust Workflow for Acquiring and Preprocessing Ambient Vibration Data from Small Aperture Ocean Bottom Seismometer Arrays to Extract Scholte and Love Waves Phase-Velocity Dispersion Curves

2021 ◽  
Author(s):  
Agostiny Marrios Lontsi ◽  
Anastasiia Shynkarenko ◽  
Katrina Kremer ◽  
Manuel Hobiger ◽  
Paolo Bergamo ◽  
...  
Keyword(s):  
Phase Velocity ◽  
Surface Waves ◽  
Dispersion Curve ◽  
Velocity Dispersion ◽  
Love Waves ◽  
Ambient Vibration ◽  
Ocean Bottom ◽  
Small Aperture ◽  
Phase Velocity Dispersion ◽  
Phase Velocity Dispersion Curve

AbstractThe phase-velocity dispersion curve (DC) is an important characteristic of the propagation of surface waves in sedimentary environments. Although the procedure for DC estimation in onshore environments using ambient vibration recordings is well established, the DC estimation in offshore environments using Ocean Bottom Seismometers (OBS) array recordings of ambient vibrations presents three additional challenges: (1) the localization of sensors, (2) the orientation of the OBS horizontal components, and (3) the clock error. Here, we address these challenges in an inherent preprocessing workflow to ultimately extract the Love and Scholte wave DC from small aperture OBS array measurements performed between 2018 and 2020 in Lake Lucerne (Switzerland). The arrays have a maximum aperture of 679 m and a maximum deployment water depth of 81 m. The challenges related to the OBS location on the lake floor are addressed by combining the multibeam bathymetry map and the backscatter image for the investigated site with the differential GPS coordinates of the OBS at recovery. The OBS measurements are complemented by airgun surveys. Airgun data are first used to estimate the misorientation of the horizontal components of the OBS and second to estimate the clock error. To assess the robustness of the preprocessing workflow, we use two array processing methods, namely the three-component high-resolution frequency-wavenumber and the interferometric multichannel analysis of surface waves, to estimate the dispersion characteristics of the propagating Scholte and Love waves for one of the OBS array sites. The results show the effectiveness of the preprocessing workflow. We observe the phase-velocity dispersion curve branches in the frequency range between 1.2 and 3.2 Hz for both array processing techniques.

scholarly journals Repulsion of phase‐velocity dispersion curves and the nature of plate vibrations

1993 ◽  
Vol 94 (3) ◽  
pp. 1877-1877
Author(s):  
B. Hosten ◽  
M. Deschamps ◽  
A. Gérard ◽  
H. Überall
Keyword(s):  
Phase Velocity ◽  
Velocity Dispersion ◽  
Dispersion Curves ◽  
Plate Vibrations ◽  
Phase Velocity Dispersion
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