scholarly journals Horizontally orthogonal distributed acoustic sensing array for earthquake- and ambient-noise-based multichannel analysis of surface waves

2020 ◽  
Vol 222 (3) ◽  
pp. 2147-2161
Author(s):  
Bin Luo ◽  
Whitney Trainor-Guitton ◽  
Ebru Bozdağ ◽  
Lisa LaFlame ◽  
Steve Cole ◽  
...  
Keyword(s):  
Rayleigh Wave ◽  
Surface Waves ◽  
Love Wave ◽  
Ambient Noise ◽  
Wave Dispersion ◽  
Wave Component ◽  
Multichannel Analysis ◽  
Distributed Acoustic Sensing ◽  
Love Wave Dispersion

SUMMARY A 2-D orthogonal distributed acoustic sensing (DAS) array designed for seismic experiments was buried horizontally beneath the Kafadar Commons Geophysical Laboratory on the Colorado School of Mines campus at Golden, Colorado. The DAS system using straight fibre-optic cables is a cost-efficient technology that enables dense seismic array deployment for long-term seismic monitoring, favouring both earthquake-based and ambient-noise-based surface wave analysis for subsurface characterization. In our study, the horizontally orthogonal DAS array records ambient noise data for a period of about two months from November 2018 to January 2019. During this time, the array also detected seismic signals from an ML3.6 earthquake at Glenwood Springs, Colorado, which exhibit opposite signal polarities in the orthogonal DAS section recordings. We derive the transformation matrix for DAS strain measurements in horizontally orthogonal cables to retrieve both Rayleigh and Love wave dispersion information from the single-component DAS signals using the 2-D multichannel analysis of surface waves method. In addition, ambient noise interferometry is applied to long-term DAS noise recordings. Our theoretical derivation demonstrates that Rayleigh and Love wave Green's functions are coupled in the noise cross-correlation functions (NCFs) of DAS receiver pairs. Stacking NCFs over the horizontally orthogonal DAS array can constructively recover the radial Rayleigh wave component but destructively suppress the Love wave component. The multimodal Monte Carlo inversion of the earthquake-based Rayleigh wave and Love wave dispersion measurements and the noise-based Rayleigh wave measurement reveals a 1-D layered structure that agrees qualitatively with geological surveys of the site. Our study demonstrates that although straight fibre-optic cables lack broadside sensitivity, using appropriate DAS array configuration and seismic array methods can extend the seismic acquisition ability of DAS and enable its application to a broad range of scenarios.

Revisiting levees in southern Texas using Love-wave multichannel analysis of surface waves with the high-resolution linear Radon transform

2017 ◽  
Vol 5 (3) ◽  
pp. T287-T298 ◽  
Author(s):  
Julian Ivanov ◽  
Richard D. Miller ◽  
Daniel Feigenbaum ◽  
Sarah L. C. Morton ◽  
Shelby L. Peterie ◽  
...  
Keyword(s):  
High Resolution ◽  
Rayleigh Wave ◽  
Surface Waves ◽  
Radon Transform ◽  
Seismic Data ◽  
Love Wave ◽  
S Wave ◽  
Multichannel Analysis ◽  
Masw Method ◽  
Wave Methods

Shear-wave velocities were estimated at a levee site by inverting Love waves using the multichannel analysis of surface waves (MASW) method augmented with the high-resolution linear Radon transform (HRLRT). The selected site was one of five levee sites in southern Texas chosen for the evaluation of several seismic data-analysis techniques readily available in 2004. The methods included P- and S-wave refraction tomography, Rayleigh- and Love-wave surface-wave analysis using MASW, and P- and S-wave cross-levee tomography. The results from the 2004 analysis revealed that although the P-wave methods provided reasonable and stable results, the S-wave methods produced surprisingly inconsistent shear-wave velocity [Formula: see text] estimates and trends compared with previous studies and borehole investigations. In addition, the Rayleigh-wave MASW method was nearly useless within the levee due to the sparsity of high frequencies in fundamental-mode surface waves and complexities associated with inverting higher modes. This prevented any reliable [Formula: see text] estimates for the levee core. Recent advances in methodology, such as the HRLRT for obtaining higher resolution dispersion-curve images with the MASW method and the use of Love-wave inversion routines specific to Love waves as part of the MASW method, provided the motivation to extend the 2004 original study by using horizontal-component seismic data for characterizing the geologic properties of levees. Contributions from the above-mentioned techniques were instrumental in obtaining [Formula: see text] estimates from within these levees that were very comparable with the measured borehole samples. A Love-wave approach can be a viable alternative to Rayleigh-wave MASW surveys at sites where complications associated with material or levee geometries inhibit reliable [Formula: see text] results from Rayleigh waves.

Rayleigh- and Love-wave dispersion up to 140-second-period range in the Indonesia-Philippine region

1975 ◽  
Vol 65 (2) ◽  
pp. 507-521
Author(s):  
Harsh K. Gupta ◽  
Kazuo Hamada
Keyword(s):  
Rayleigh Wave ◽  
Group Velocity ◽  
Love Wave ◽  
Active Regions ◽  
Wave Dispersion ◽  
Wave Group ◽  
Period Range ◽  
Moving Window Analysis ◽  
Love Wave Dispersion ◽  
Group Velocities

abstract Group velocities for Rayleigh waves extending to 140-sec-period range have been determined for 10 paths in the Indonesia-Philippine region using moving window analysis. The group velocities for five of these paths have been determined from the vertical as well as the longitudinal components and the values obtained from the two components tally with each other. It has also been possible to obtain Love-wave group velocities for three of these paths. On the basis of group-velocity values and regions covered, the observed Rayleigh-wave group-velocity data could be divided into three groups. The first group includes data for paths mostly confined to deep ocean and the observed data could be explained by standard oceanic models such as 8099. The second group includes data for paths lying partially within seismically active regions and models ARC-1 and ALRDG-9 fit with these data. The third group shows still lower group velocities for paths entirely confined to seismically active regions. The shear velocities inferred from Love-wave dispersion data are higher than those inferred from Rayleigh-wave data. In general, the group velocities varied greatly within small distances even in the longer period range, indicating strong lateral heterogeneities in the mantle.

Multichannel analysis of Love waves in a 3D seismic acquisition system

Geophysics ◽  
2016 ◽  
Vol 81 (5) ◽  
pp. EN67-EN74 ◽  
Author(s):  
Yudi Pan ◽  
Jianghai Xia ◽  
Yixian Xu ◽  
Lingli Gao
Keyword(s):  
Love Wave ◽  
Wave Dispersion ◽  
Love Waves ◽  
3D Seismic ◽  
Near Surface ◽  
Wave Data ◽  
Multichannel Analysis ◽  
Seismic Acquisition ◽  
Love Wave Dispersion ◽  
Receiver Point

Multichannel analysis of Love waves (MALW) analyzes high-frequency Love waves to determine near-surface S-wave velocities, and it is getting increasing attention in the near-surface geophysics and geotechnique community. Based on 2D geometry spread, in which sources and receivers are placed along the same line, current MALW fails to work in a 3D seismic acquisition system. This is because Love-wave particle motion direction is perpendicular to its propagation direction, which makes it difficult to record a Love-wave signal in 3D geometries. We have developed a method to perform MALW with data acquired in 3D geometry. We recorded two orthogonal horizontal components (inline and crossline components) at each receiver point at the same time. By transforming the raw data from rectangular coordinates (inline and crossline components) to radial-transverse coordinates (radial and transverse components), we recovered Love-wave data along the transverse direction at each receiver point. To achieve a Love-wave dispersion curve, the recovered Love-wave data were first transformed into a conventional receiver offset domain, and then transformed into the frequency-velocity ([Formula: see text]-[Formula: see text]) domain. Love-wave dispersion curves were picked along the continuous dispersive energy peaks in the [Formula: see text]-[Formula: see text] domain. The validity of our proposed method was verified by two synthetic tests and a real-world example.

scholarly journals Computation of surface wave dispersion for multilayered anisotropic media

1962 ◽  
Vol 52 (2) ◽  
pp. 321-332 ◽  
Author(s):  
David G. Harkrider ◽  
Don L. Anderson
Keyword(s):  
Surface Wave ◽  
Rayleigh Wave ◽  
Rayleigh Waves ◽  
Love Wave ◽  
Transversely Isotropic ◽  
Wave Dispersion ◽  
Surface Wave Dispersion ◽  
Independent Evidence ◽  
Anisotropic Layers ◽  
Love Wave Dispersion

ABSTRACT With the program described in this paper it is now possible to compute surface wave dispersion in a solid heterogeneous halfspace containing up to 200 anisotropic layers. Certain discrepancies in surface wave observations, such as disagreement between Love and Rayleigh wave data and other independent evidence, suggest that anisotropy may be important in some seismological problems. In order to study the effect of anisotropy on surface wave dispersion a program was written for an IBM 7090 computer which will compute dispersion curves and displacements for Rayleigh waves in a layered halfspace in which each layer is transversely isotropic. A simple redefinition of parameters makes it possible to use existing programs to compute Love wave dispersion.

Love-Wave dispersion and the structure of the Pacific Basin*

1954 ◽  
Vol 44 (1) ◽  
pp. 1-5
Author(s):  
Jack Foord Evernden
Keyword(s):  
Love Wave ◽  
Wave Dispersion ◽  
Love Waves ◽  
Pacific Basin ◽  
Layer Model ◽  
Basin Structure ◽  
Dispersion Data ◽  
The Pacific ◽  
Love Wave Dispersion

abstract By use of the Love-Wave dispersion data for the earthquake of 29 September 1946 (Lat. 5° S, Long. 154° E), a three-layer model of Pacific Basin structure has been derived. The periods of the Love Waves observed varied continuously from 45 seconds to 7 seconds. The model consists of: (a) 2.5 km. with VS equal to 2.31 km/sec.; (b) 11 km. with VS equal to 3.87 km/sec.; (c) bottom with VS equal to 4.52 km/sec. The differences between this model and that found by Raitt using refraction measurements are discussed.

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