scholarly journals Emergence of broadband Rayleigh waves from correlations of the ambient seismic noise

2004 ◽  
Vol 31 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. M. Shapiro ◽  
M. Campillo
Keyword(s):  
Rayleigh Waves ◽  
Seismic Noise ◽  
Ambient Seismic Noise

scholarly journals Ambient seismic noise tomography to build up a 3D shear-wave velocity model

2021 ◽  
Vol 22 (2) ◽  
pp. 1-9 ◽  
Author(s):  
Martín Cárdenas Soto ◽  
José Piña Flores ◽  
David Escobedo Zenil ◽  
Jesús Sánchez González ◽  
José Antonio Martínez González
Keyword(s):  
Rayleigh Waves ◽  
Seismic Noise ◽  
Velocity Model ◽  
Ambient Seismic Noise ◽  
Lava Tube ◽  
Low Velocity ◽  
Rectangular Array ◽  
Velocity Anomaly ◽  
Adjacent Building ◽  
Tomography Method

To explore the usefulness of the ambient seismic noise tomography method for characterizing the subsoil surface structure, in this study, we apply this method to contribute to geotechnical decision-making in the construction of a school building. We used a rectangular array (36x56 m) of 48-4.5 Hz vertical geophones and produce surface wave tomographies from the travel times of Rayleigh waves extracted by cross-correlation of seismic noise. We determined a final 3D Vs model using 1D models derived from the inversion of dispersion curves obtained from the tomography maps for different frequencies. The 3D model shows an excellent resolution (vertical and lateral); we observe critical velocity contrasts in the range of 2 to 15 m deep. At depths higher than 15 m, the velocity has values close to 900 m/s; however, we observe a low-velocity anomaly associated with a lava tube or crack that seems to continue under an adjacent building.

scholarly journals A Linear Inversion Approach to Measuring the Composition and Directionality of the Seismic Noise Field

2021 ◽  
Vol 13 (16) ◽  
pp. 3097
Author(s):  
Patrick M. Meyers ◽  
Tanner Prestegard ◽  
Vuk Mandic ◽  
Victor C. Tsai ◽  
Daniel C. Bowden ◽  
...  
Keyword(s):  
Real World ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Angular Resolution ◽  
Three Dimensional ◽  
Body Waves ◽  
Ambient Seismic Noise ◽  
Linear Inversion ◽  
Modal Composition ◽  
Cross Correlations

We develop a linear inversion technique for measuring the modal composition and directionality of ambient seismic noise. The technique draws from similar techniques used in astrophysics and gravitational-wave physics, and relies on measuring cross-correlations between different seismometer channels in a seismometer array. We characterize the sensitivity and the angular resolution of this technique using a series of simulations and real-world tests. We then apply the technique to data acquired by the three-dimensional seismometer array at the Homestake mine in Lead, SD, to estimate the composition and directionality of the seismic noise at microseism frequencies. We show that, at times of low-microseism amplitudes, noise is dominated by body waves (P and S), while at high-microseism times, the noise is dominated by surface Rayleigh waves.

scholarly journals Using multicomponent ambient seismic noise cross-correlations to identify higher mode Rayleigh waves and improve dispersion measurements

2020 ◽  
Vol 222 (3) ◽  
pp. 1590-1605 ◽  
Author(s):  
Avinash Nayak ◽  
Clifford H Thurber
Keyword(s):  
Rayleigh Wave ◽  
Group Velocity ◽  
Particle Motion ◽  
Fundamental Mode ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Vertical Plane ◽  
Ambient Seismic Noise ◽  
Cross Correlations ◽  
The Individual

SUMMARY Ambient seismic noise cross-correlation with three-component sensors yields a nine-component empirical Green's tensor, in which four components of the radial–vertical plane contain Rayleigh waves. We exploit the retrograde elliptical nature of particle motion of the fundamental mode Rayleigh wave to correct the phase of the four radial–vertical components and stack them to obtain an average fundamental mode Rayleigh-wave time-series. This technique can suppress incoherent noise and wave packets that do not follow the targeted elliptical particle motion. The same technique can be used to isolate the first higher mode Rayleigh wave that follows prograde elliptical particle motion. We first demonstrate the effectiveness of the method on synthetic waveforms and then apply it on noise cross-correlations computed in Central California. Using this method, we isolate 1st higher mode Rayleigh waves on noise cross-correlations in the Great Valley, California, which provides new phase velocity constraints for estimating velocity structure in the sedimentary basin. We also obtain improved estimates of fundamental mode Rayleigh-wave dispersion for surface-wave tomography. The waveforms stacked assuming retrograde particle motion return at least ∼20 per cent more group velocity dispersion measurements satisfying a minimum signal-to-noise ratio (SNR) criterion than the individual components for periods ∼4–18 s. For equivalent group velocity measurements, SNR for the stacked estimate of the fundamental mode Rayleigh wave is on average 40 per cent greater than that measured on the individual components at periods less than 10 s. The technique also provides an easy way to detect large errors in sensor orientation.

scholarly journals Shear wave velocity structure beneath Bandung basin, West Java, Indonesia from ambient noise tomography

2019 ◽  
Author(s):  
B Pranata ◽  
T Yudistira ◽  
S Widiyantoro ◽  
B Brahmantyo ◽  
P R Cummins ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Velocity Structure ◽  
Ambient Seismic Noise ◽  
Upper Crust ◽  
West Java ◽  
Shear Wave Velocity Structure

Summary We investigated the seismic shear wave velocity structure of the upper crust beneath the Bandung area in West Java, Indonesia, using ambient seismic noise tomography. We installed 60 seismographs to record ambient seismic noise continuously in the city of Bandung and its surrounding area for 8 months. After inter-station cross-correlation of recordings of ambient seismic noise, we obtained empirical Green's functions for Rayleigh waves. Group velocity dispersion curves for Rayleigh waves between periods of 1 s and 8 s were measured on each inter-station path by applying the multiple filter analysis method with phase-matched processing. The spatial variation of group velocities shows a good correlation with the geological structure of the Bandung Basin. The Rayleigh wave dispersion maps were inverted to obtain the 1D shear wave velocity profiles beneath each station, which were interpolated to infer a pseudo-3D structure under the study region. The results show that the Bandung Basin has a thick layer of sediment. Along the northern, eastern and southern mountains surrounding the Bandung Basin there is high-velocity structure, except to the west of the Tangkuban Parahu volcano, where a massive low-velocity structure extending throughout the upper crust might indicate the presence of fluids or partial melts.

Sign in / Sign up

Export Citation Format

Share Document