Frequency-dependent attenuation of P and S waves in Yunnan region

2005 ◽  
Vol 18 (6) ◽  
pp. 632-642 ◽  
Author(s):  
Qin-cai Wang ◽  
Jie Liu ◽  
Si-hua Zheng ◽  
Zhang-li Chen
Keyword(s):  
Frequency Dependent ◽  
S Waves ◽  
Yunnan Region

Frequency-dependent Attenuation of High-frequency P and S Waves in the Upper Crust in Western Nagano, Japan

1998 ◽  
Vol 153 (2-4) ◽  
pp. 489-502 ◽  
Author(s):  
K. Yoshimoto ◽  
H. Sato ◽  
Y. Iio ◽  
H. Ito ◽  
T. Ohminato ◽  
...  
Keyword(s):  
High Frequency ◽  
Upper Crust ◽  
Frequency Dependent ◽  
S Waves

scholarly journals Frequency-dependent attenuation of P and S waves in northeast India

2010 ◽  
Vol 183 (2) ◽  
pp. 1052-1060 ◽  
Author(s):  
Simanchal Padhy ◽  
N. Subhadra
Keyword(s):  
Northeast India ◽  
Frequency Dependent ◽  
S Waves

scholarly journals Frequency-Dependent Attenuation of P and S Waves in Southern California

2018 ◽  
Vol 123 (7) ◽  
pp. 5814-5830 ◽  
Author(s):  
Yu-Pin Lin ◽  
Thomas H. Jordan
Keyword(s):  
Southern California ◽  
Frequency Dependent ◽  
S Waves

Effect of fluids and frequencies on Poisson’s ratio of sandstone samples

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. D183-D195 ◽  
Author(s):  
Lucas Pimienta ◽  
Jérôme Fortin ◽  
Yves Guéguen
Keyword(s):  
Frequency Dependence ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Fluid Viscosity ◽  
S Wave ◽  
Standard Samples ◽  
Frequency Dependent ◽  
S Waves ◽  
Fontainebleau Sandstone ◽  
Dry Conditions

Poisson’s ratio [Formula: see text] is an important parameter when interpreting measured geophysical and seismic data. For an isotropic medium, it directly relates to the ratio of P- and S-wave velocities. We have measured [Formula: see text] as a function of pressure and frequency in fluid-saturated sandstones. The method of measuring [Formula: see text] was first tested as a function of pressure and frequency using standard samples. The phase shift [Formula: see text] between radial and axial strains was also measured. For all standard samples, such as the linear viscoelastic Plexiglas, the data indicated that [Formula: see text] correlated with [Formula: see text] and related to a dissipation on [Formula: see text]. Then, [Formula: see text] and [Formula: see text] were measured as a function of pressure and frequency for two dry and fluid-saturated Fontainebleau sandstone samples. Under dry conditions, no frequency dependence and very small pressure dependence were observed. Unusual behaviors were observed under fluid-saturated conditions. In particular, [Formula: see text] of one sample indicated a frequency-dependent bell-shaped dispersion under water and glycerin saturation that correlated with peaks in [Formula: see text]. Plotting the measurements as a function of apparent frequency (i.e., normalizing by the fluid viscosity) indicated a good fit between the water- and glycerin-saturated measurements. The bell-shaped dispersion in [Formula: see text] that was observed for one particular sandstone held for all effective pressures. These variations fully correlated with the peaks of [Formula: see text] observed. Our results can be interpreted using fluid flow and effective medium theories in the case of a porous microcracked rock. Drained/undrained and relaxed/unrelaxed transitions have frequency and magnitude of variations that are consistent with the measurements. The rock sample microcrack density strongly affects this frequency dependence. The inferred [Formula: see text] ratio at low effective pressures also indicates a large frequency-dependent bell-shaped dispersion. The parameter [Formula: see text] is a clear indicator of the frequency-dependent dissipation of [Formula: see text] and relates to the attenuation of P- and S-waves.

Attenuation of Broadband P and S Waves in Tonga: Observations of Frequency Dependent Q

1998 ◽  
Vol 153 (2-4) ◽  
pp. 345-375 ◽  
Author(s):  
M. P. Flanagan ◽  
D. A. Wiens
Keyword(s):  
Frequency Dependent ◽  
S Waves

scholarly journals Frequency-dependent attenuation of S-waves in the Kanto region, Japan

2009 ◽  
Vol 61 (9) ◽  
pp. 1067-1075 ◽  
Author(s):  
Kazuo Yoshimoto ◽  
Mariko Okada
Keyword(s):  
Frequency Dependent ◽  
S Waves ◽  
Kanto Region

scholarly journals Frequency dependent attenuation of seismic waves for Delhi and surrounding area, India

2015 ◽  
Vol 58 (2) ◽  
Author(s):  
Babita Sharma ◽  
Prasantha Chingtham ◽  
Anup K. Sutar ◽  
Sumer Chopra ◽  
Haldhar P. Shukla
Keyword(s):  
Seismic Waves ◽  
Quality Factors ◽  
P Waves ◽  
Frequency Dependent ◽  
S Waves ◽  
Intrinsic Attenuation ◽  
Attenuation Parameter ◽  
Coda Normalization Method ◽  
Coda Normalization ◽  
Single Backscattering Model

<p align="left">The attenuation properties of Delhi &amp; surrounding region have been investigated using 6<em>2</em> local earthquakes recorded at nine stations. The frequency dependent quality factors <em>Q</em><em><sub>a</sub></em> (using P-waves) and <em>Q</em><em><sub>b</sub></em> (using S-waves) have been determined using the coda normalization method. Quality factor of coda-waves (<em>Q<sub>c</sub></em>) has been estimated using the single backscattering model in the frequency range from 1.5 Hz to 9 Hz. Wennerberg formulation has been used to estimate <em>Q<sub>i</sub></em> (intrinsic attenuation parameter) and <em>Q<sub>s</sub></em> (scattering attenuation parameter) for the region. The values <em>Q</em><em><sub>a</sub>, Q</em><em><sub>b, </sub>Q<sub>c, </sub>Q<sub>i</sub> and Q<sub>s</sub></em> estimated are frequency dependent in the range of 1.5Hz-9Hz. Frequency dependent relations are estimated as <em>Q</em><em><sub>a</sub>=52f<sup>1.03</sup>, Q</em><em><sub>b</sub>=98f<sup>1.07</sup> and Q<sub>c</sub>=158f<sup>0.97</sup></em>. <em>Q<sub>c</sub></em> estimates lie in between the values of <em>Q<sub>i</sub></em> and <em>Q<sub>s</sub></em> but closer to <em>Q<sub>i</sub></em> at all central frequencies. Comparison between <em>Q<sub>i</sub> </em>and <em>Q<sub>s</sub></em> shows that intrinsic absorption is predominant over scattering for Delhi and surrounding region. </p>

Frequency-dependent Attenuation of High-frequency P and S Waves in the Upper Crust in Western Nagano, Japan

1998 ◽  
pp. 489-502
Author(s):  
Kazuo Yoshimoto ◽  
Haruo Sato ◽  
Yoshihisa Iio ◽  
Hisao Ito ◽  
Takao Ohminato ◽  
...  
Keyword(s):  
High Frequency ◽  
Upper Crust ◽  
Frequency Dependent ◽  
S Waves

Analysis of S waves singularity points in porous rock with two orthogonal sets of mesoscale fractures

2021 ◽  
Vol 228 (1) ◽  
pp. 604-619
Author(s):  
Shuo Pang ◽  
Alexey Stovas ◽  
Huilin Xing
Keyword(s):  
Seismic Data ◽  
Symmetry Plane ◽  
Fracture Density ◽  
Porous Rock ◽  
Frequency Dependent ◽  
Anisotropic Models ◽  
S Waves ◽  
Phase Velocities ◽  
Singularity Point ◽  
Fracture Scale

SUMMARY The shear waves phase velocity surfaces in orthorhombic (ORT) and lower symmetry anisotropic models touch each other in one or more points resulting in so called singularity points or acoustic axes. These singularity points result in dramatic changes of velocities, amplitudes and polarizations creating problems in seismic data processing and analysis. Considering the frequency-dependent anisotropy due to mesoscale fractures in Chapman's model, we describe the singularity points in porous rock with two orthogonal sets of mesoscale fractures. First, we give the equations for frequency-dependent phase velocities of P, S1 and S2 waves in this anelastic ORT media. Then, we derive the expressions for frequency-dependent singularity points within the symmetry planes and discuss the conditions to detect the existence of singularity point. Finally, the influences of frequency, porosity, fracture density, fracture scale and saturating fluid style on the positions of singularity points within the symmetry plane are investigated.

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