Seismoelectric Surface-Wave Analysis for Characterization of Formation Properties, using Dispersive Relative Spectral Amplitudes

Geophysics ◽  
2021 ◽  
pp. 1-25
Author(s):  
N. Grobbe ◽  
S. A. L. de Ridder
Keyword(s):  
Surface Wave ◽  
Body Wave ◽  
Electrical Potential ◽  
Relative Strength ◽  
Body Waves ◽  
Fluid Viscosity ◽  
Near Surface ◽  
Em Field ◽  
Seismic Body Waves

We study seismoelectric (SE) surface-wave signals and find that they can be used to infer changes in the SE coupling properties at depth. Seismoelectric surface-wave signals have much higher amplitudes than seismoelectric body-wave signals. We propose to measure both the seismic and the electrical potential or electromagnetic (EM) field along the surface of the Earth. We use Dispersive Relative Spectral Amplitudes (DRSA) that measure the frequency-dependent relative strength of electrical signals versus seismic signals associated with seismoelectric surface-wave signals. We show that the DRSA have sensitivity to contrasts in the electrokinetic coupling coefficient and other relevant petrophysical properties at depth. Our discovery can mitigate the major limitation that plagues body wave-based SE methods: the relative weakness of the converted, EM signals from seismic body waves. We envision applications to characterize subsurface rock, fluid and fluid-flow properties (e.g. porosity, permeability, and dynamic fluid viscosity, salinity) in the near surface, for aquifers, and shallow geothermal reservoirs.

scholarly journals Seismic Characterization of the Nevada National Security Site Using Joint Body Wave, Surface Wave, and Gravity Inversion

2019 ◽  
Vol 110 (1) ◽  
pp. 110-126
Author(s):  
Leiph Preston ◽  
Christian Poppeliers ◽  
David J. Schodt
Keyword(s):  
Surface Wave ◽  
National Security ◽  
Surface Waves ◽  
Body Wave ◽  
Wave Dispersion ◽  
The Body ◽  
Body Waves ◽  
Gravity Inversion ◽  
Surface Wave Dispersion ◽  
Near Surface

ABSTRACT As a part of the series of Source Physics Experiments (SPE) conducted on the Nevada National Security Site in southern Nevada, we have developed a local-to-regional scale seismic velocity model of the site and surrounding area. Accurate earth models are critical for modeling sources like the SPE to investigate the role of earth structure on the propagation and scattering of seismic waves. We combine seismic body waves, surface waves, and gravity data in a joint inversion procedure to solve for the optimal 3D seismic compressional and shear-wave velocity structures and earthquake locations subject to model smoothness constraints. Earthquakes, which are relocated as part of the inversion, provide P- and S-body-wave absolute and differential travel times. Active source experiments in the region augment this dataset with P-body-wave absolute times and surface-wave dispersion data. Dense ground-based gravity observations and surface-wave dispersion derived from ambient noise in the region fill in many areas where body-wave data are sparse. In general, the top 1–2 km of the surface is relatively poorly sampled by the body waves alone. However, the addition of gravity and surface waves to the body-wave dataset greatly enhances structural resolvability in the near surface. We discuss the methodology we developed for simultaneous inversion of these disparate data types and briefly describe results of the inversion in the context of previous work in the region.

Effects of thin soft layers on body waves

1969 ◽  
Vol 59 (5) ◽  
pp. 2071-2078
Author(s):  
Tom Landers ◽  
Jon F. Claerbout
Keyword(s):  
Surface Wave ◽  
Upper Mantle ◽  
Body Wave ◽  
Wave Dispersion ◽  
Soft Material ◽  
Body Waves ◽  
Surface Wave Dispersion ◽  
Wave Data ◽  
Use Of Time ◽  
Surface Wave Data

abstract The inability of simple layered models to fit both Rayleigh wave and Love wave data has led to the proposal of an upper mantle interleaved with thin soft horizontal layers. Since surface-wave dispersion is not sensitive to the distribution of soft material but only to the fraction of soft material a variety of models is possible. The solution to this indeterminancy is found through body-wave analysis. It is shown that body waves are dispersed according to the thinness and softness of the layers. Three models, each of which satisfy all surface-wave data, are examined. Transmission seismograms calculated for these models show one to be impossible, one improbable and the other possible. Synthesis of the seismograms is accomplished through the use of time domain theory as the complicated frequency response of the models makes a frequency oriented Haskell-Thompson approach impractical.

3D elastic full-waveform inversion of surface waves in the presence of irregular topography using an envelope-based misfit function

Geophysics ◽  
2018 ◽  
Vol 83 (1) ◽  
pp. R1-R11 ◽  
Author(s):  
Dmitry Borisov ◽  
Ryan Modrak ◽  
Fuchun Gao ◽  
Jeroen Tromp
Keyword(s):  
Surface Wave ◽  
Objective Function ◽  
Surface Waves ◽  
Large Scale ◽  
Body Wave ◽  
Waveform Inversion ◽  
Full Waveform Inversion ◽  
S Wave ◽  
Near Surface ◽  
Full Waveform

Full-waveform inversion (FWI) is a powerful method for estimating the earth’s material properties. We demonstrate that surface-wave-driven FWI is well-suited to recovering near-surface structures and effective at providing S-wave speed starting models for use in conventional body-wave FWI. Using a synthetic example based on the SEG Advanced Modeling phase II foothills model, we started with an envelope-based objective function to invert for shallow large-scale heterogeneities. Then we used a waveform-difference objective function to obtain a higher-resolution model. To accurately model surface waves in the presence of complex tomography, we used a spectral-element wave-propagation solver. Envelope misfit functions are found to be effective at minimizing cycle-skipping issues in surface-wave inversions, and surface waves themselves are found to be useful for constraining complex near-surface features.

scholarly journals Vertical force scaling in seismic source models of underground nuclear explosions

2020 ◽  
Vol 221 (1) ◽  
pp. 251-264
Author(s):  
Michael Howe ◽  
Göran Ekström ◽  
Paul G Richards
Keyword(s):  
Surface Wave ◽  
Body Wave ◽  
Scaling Factor ◽  
Body Waves ◽  
Burial Depth ◽  
Vertical Force ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Seismic Source Models ◽  
Force Scaling

SUMMARY We have reanalysed observations of body waves and surface waves for 71 well-recorded underground nuclear explosions (UNEs) that were conducted between 1977 and 1989 at the Balapan subregion of the Semipalatinsk Test Site in Kazakhstan. To reconcile differences between body-wave and surface-wave amplitudes, we solve for a scaling factor between vertical and horizontal forces in the explosion model. We find that the estimated scaling factor is anticorrelated with the scaled depth of burial for the subset of UNEs at Balapan that have published depths. The observed anticorrelation and the inferred variations in force scaling suggest that recorded surface-wave amplitudes are significantly influenced by UNE burial depth as well as by previously recognized tectonic release. As part of our analysis, we revisit the relationship between teleseismic mb(P) and yield for UNEs at Balapan, and discuss the physical basis for effectiveness of the mb–MS discriminant.

scholarly journals Teleseismic analysis of the 1980 Mammoth Lakes earthquake sequence

1982 ◽  
Vol 72 (4) ◽  
pp. 1093-1109
Author(s):  
Jeffrey W. Given ◽  
Terry C. Wallace ◽  
Hiroo Kanamori
Keyword(s):  
Surface Wave ◽  
Sierra Nevada ◽  
Body Wave ◽  
The Body ◽  
Body Waves ◽  
Earthquake Sequence ◽  
Local Data ◽  
Fault Plane Solutions ◽  
Principal Axes ◽  
Mammoth Lakes

abstract The source mechanisms of the three largest events of the 1980 Mammoth Lakes earthquake sequence have been determined using surface waves recorded on the global digital seismograph network and the long-period body waves recorded on the WWSSN network. Although the fault-plane solutions from local data (Cramer and Toppozada, 1980; Ryall and Ryall, 1981) suggest nearly pure left-lateral strike-slip on north-south planes, the teleseismic waveforms require a mechanism with oblique slip. The first event (25 May 1980, 16h 33m 44s) has a mechanism with a strike of N12°E, dip of 50°E, and a rake of −35°. The second event (27 May 19h 44m 51s) has a mechanism with a strike of N15°E, dip of 50°, and a slip of −11°. The third event (27 May, 14h 50m 57s) has a mechanism with a strike of N22°E, dip of 50°, and a rake of −28°. The first event is the largest and has a moment of 2.9 × 1025 dyne-cm. The second and third events have moments of 1.3 and 1.1 × 1025 dyne-cm, respectively. The body- and surface-wave moments for the first and third events agree closely while for the second event the body-wave moment (approximately 0.6 × 1025 dyne-cm) is almost a factor of 3 smaller than the surface-wave moment. The principal axes of extension of all three events is in the approximate direction of N65°E which agrees with the structural trends apparent along the eastern front of the Sierra Nevada.

The effects of radiation patterns on magnitude estimates

1970 ◽  
Vol 60 (2) ◽  
pp. 503-516 ◽  
Author(s):  
David von Seggern
Keyword(s):  
Surface Wave ◽  
Radiation Pattern ◽  
Body Wave ◽  
Body Waves ◽  
Force System ◽  
Pattern Theory ◽  
Double Couple ◽  
Effects Of Radiation ◽  
Body Wave Magnitude ◽  
Selection Of

abstract With a double-couple force system as a model of an earthquake source mechanism, the radiation pattern theory of Ben-Menahem is employed to show that the far-field measurement of its strength can theoretically vary by more than a magnitude unit using either surface waves or body waves depending upon the angles of slip motion and fault dip for a source at a constant depth. The magnitude values determined by surface and body waves do not change linearly in relation to slip and dip angles nor do they change linearly in relation to one another. Random selection of locations within the radiation pattern is used to determine the extent of scatter in magnitude determinations which could be attributed to station distribution relative to the source. The scatter in surface-wave versus body-wave magnitude plots for earthquakes could be severe if only a few stations are used to obtain average magnitude values. A method of obtaining consistent estimates of surface-wave magnitude in practice is discussed.

Near-surface scattering effects observed with a high-frequency phased array at Pinyon Flats, California

1998 ◽  
Vol 88 (6) ◽  
pp. 1548-1560
Author(s):  
Frank L. Vernon ◽  
Gary L. Pavlis ◽  
Tom J. Owens ◽  
Dan E. McNamara ◽  
Paul N. Anderson
Keyword(s):  
Surface Wave ◽  
Wave Field ◽  
Particle Motion ◽  
High Frequency ◽  
Body Wave ◽  
Three Dimensional ◽  
Wave Guide ◽  
Surface Scattering ◽  
Near Surface ◽  
Frequency Wave

Abstract Analysis of data collected by a high-frequency array experiment conducted at Pinyon Flat in southern California provides strong evidence that the high-frequency wave field from local earthquakes at this hard-rock site are strongly distorted by near-surface scattering. The seismic array we deployed consisted of 60, 2-Hz natural frequency, three-component sensors deployed in a three-dimensional array. Two of the sensors were located in boreholes at 150 and 275 m depth. The other 58 sensors were deployed in an areal array above these boreholes. Thirty-six of these were deployed in a 6-by-6 element grid array with a nominal spacing of 7 m centered over the borehole sensors. The remaining 22 seismometers were laid out in two 11-element linear arrays radiating outward from the grid. Coherence calculations reveal a rapid loss of coherence at frequencies over 15 Hz at all but the shortest length scales of this array. Three-dimensional visualization techniques were used to closely examine the spatial stability of particle motions of P and S waves. This reveals systematic variations of particle motion across the array in which the particle motion tracks tilt drastically away from the backazimuth expected for an isotropic medium. These variations, however, are frequency dependent. Below around 8 Hz, the particle motions become virtually identical for all stations. At progressively higher frequencies, the wave-field particle motion becomes increasingly chaotic. Frequency-wave-number analysis of these data provide quantitative measures of the same phenomena. We find that direct wave f-k spectra are bathed in a background of signal-generated noise that varies from 10 to 30 dB down from the direct arrival signal. This signal-generated noise appears to be nearly white in wavenumber indicating the wavelength of this “noise” on the scale of tens of meters and less. Refraction measurements we made on two lines crisscrossing the array reveal that the weathered layer velocities are highly variable and define a very strong wave guide. Measured surface P-wave velocities varied from 400 to 1300 m/sec, and velocities at depth of approximately 15 m varied from 1600 to 2700 m/sec. Previous measurements in the boreholes showed that the intact granite below about 65 m depth has a velocity of approximately 5400 m/sec. These results demonstrate the extreme velocity contrast and degree of velocity heterogeneity of the near surface at this site. We conclude that all the observations we made can be explained by strong scattering of incident body-wave signals into a complex mishmash of body-wave and surface-wave modes in this heterogeneous near-surface wave guide.

Near-surface imaging using ambient-noise body waves

2016 ◽  
Vol 4 (3) ◽  
pp. SJ55-SJ65 ◽  
Author(s):  
Pascal Edme ◽  
David F. Halliday
Keyword(s):  
Ambient Noise ◽  
Body Wave ◽  
Synthetic Data ◽  
Real Data ◽  
Body Waves ◽  
Seismic Survey ◽  
Subsurface Imaging ◽  
Near Surface ◽  
Deconvolution Technique ◽  
Zero Offset

We have introduced a workflow that allows subsurface imaging using upcoming body-wave arrivals extracted from ambient-noise land seismic data. Rather than using the conventional seismic interferometry approach based on correlation, we have developed a deconvolution technique to extract the earth response from the observed periodicity in the seismic traces. The technique consists of iteratively applying a gapped spiking deconvolution, providing multiple-free images with higher resolution than conventional correlation. We have validated the workflow for zero-offset traces with simple synthetic data and real data recorded during a small point-receiver land seismic survey.

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

2015 ◽  
Vol 13 (4) ◽  
pp. 315-332 ◽  
Author(s):  
Sylvain Pasquet ◽  
Ludovic Bodet ◽  
Laurent Longuevergne ◽  
Amine Dhemaied ◽  
Christian Camerlynck ◽  
...  
Keyword(s):  
Surface Wave ◽  
Wave Dispersion ◽  
Surface Wave Dispersion ◽  
Near Surface ◽  
Refraction Tomography
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