scholarly journals Body wave observations from cross-correlations of ambient seismic noise: A case study from the Karoo, RSA

2011 ◽  
Vol 38 (13) ◽  
pp. n/a-n/a ◽  
Author(s):  
T. Ryberg
Keyword(s):  
Seismic Noise ◽  
Body Wave ◽  
Ambient Seismic Noise ◽  
Cross Correlations

scholarly journals Delineation of sedimentary basin structure beneath the Banyumas Basin, Central Java, Indonesia, using ambient seismic noise tomography

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmad Setiawan ◽  
Zulfakriza Zulfakriza ◽  
Andri Dian Nugraha ◽  
Shindy Rosalia ◽  
Awali Priyono ◽  
...  
Keyword(s):  
Seismic Noise ◽  
Sedimentary Basin ◽  
Sedimentary Rocks ◽  
Vertical Component ◽  
Seismic Exploration ◽  
Ambient Seismic Noise ◽  
Central Java ◽  
Sediment Deposits ◽  
Cross Correlations ◽  
Grid Points

AbstractSubsurface images of an area with a thick volcanic layer generally cannot be well-imaged with conventional seismic exploration (seismic reflection) due to seismic wave scattering. Another method is needed to obtain an accurate subsurface image in a thick volcanic layer area. In this study, we applied ambient noise tomography (ANT) to image the shear-wave velocity (Vs) structure in the Banyumas Basin, Central Java, Indonesia, which has relatively thick volcanic layers. We aimed to delineate the sediment deposits and the sedimentary thickness in this area through the utilization of ambient seismic noise. The application of cross-correlations from ambient seismic noise has been widely applied in numerous locations to obtain a greater understanding of subsurface structures. In this study, more than 1000 pairs of vertical component cross-correlations were used to estimate the Green's Function of the Rayleigh wave. The Neighbourhood Algorithm (NA) was utilized to invert the dispersion curves at 121 grid points which were used to obtain a vertical depth profile of 1D Vs. The Vs map results show that the low Vs tend to trend in a northwest–southeast direction associated with two areas: the Majenang low, and the Citanduy low. The presence of low Vs values corresponds with Middle Miocene–Pliocene sedimentary rocks. Meanwhile, the high Vs values in this area might correspond with Oligocene–Early Miocene volcanic products and Eocene sediment. Our study was also able to reveal the thickness of sedimentary rocks in the Banyumas sedimentary basin, which is believed to have hydrocarbon potential.

Body-wave reconstruction from ambient seismic noise correlations in an underground mine

Geophysics ◽  
2015 ◽  
Vol 80 (3) ◽  
pp. KS11-KS25 ◽  
Author(s):  
Gerrit Olivier ◽  
Florent Brenguier ◽  
Michel Campillo ◽  
Richard Lynch ◽  
Philippe Roux
Keyword(s):  
Seismic Noise ◽  
Body Wave ◽  
Underground Mine ◽  
Ambient Seismic Noise

Imaging high-temperature geothermal reservoirs with ambient seismic noise tomography, a case study of the Hengill geothermal field, SW Iceland

Geothermics ◽  
2021 ◽  
Vol 96 ◽  
pp. 102207
Author(s):  
P. Sánchez-Pastor ◽  
A. Obermann ◽  
T. Reinsch ◽  
T. Ágústsdóttir ◽  
G. Gunnarsson ◽  
...  
Keyword(s):  
High Temperature ◽  
Seismic Noise ◽  
Geothermal Field ◽  
Ambient Seismic Noise ◽  
Geothermal Reservoirs

Extracting subsurface information from ambient seismic noise — A case study from Germany

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. KS13-KS31 ◽  
Author(s):  
Alexander Goertz ◽  
Barbara Schechinger ◽  
Benjamin Witten ◽  
Matthias Koerbe ◽  
Paul Krajewski
Keyword(s):  
Seismic Noise ◽  
Body Wave ◽  
Source Region ◽  
Low Frequency ◽  
Spectral Ratio ◽  
Velocity Model ◽  
Body Waves ◽  
Seismic Survey ◽  
Ambient Seismic Noise ◽  
Oil Reservoir

We analyzed ambient seismic noise from a broadband passive seismic survey acquired in an urban area in Germany. Despite a high level of anthropogenic noise, we observe lateral variations in the quasi-stationary spectra that are of natural origin and indicative of the subsurface in the survey area. The best diagnostic is the ellipticity spectrum which is the spectral ratio of the vertical over the horizontal components. Deviations of the observed spectra from a pure Rayleigh-wave ellipticity allow an approximate separation of surface-wave from body-wave components in the analyzed frequency range, distinguishing shallow (upper tens of meters) from deeper (upper three kilometers) subsurface effects. We observe an increase of vertically polarized body waves between 1 and 4 Hz that is correlated to a subsurface structure that contains an oil reservoir at about 2-km depth. We located the source of the observed body wave microtremor in depth by applying an elastic wavefield back projection and imaging technique. The method includes normalization by the impulse response of the velocity model, effects of the receiver geometry, and lateral variation of incoherent noise. The source region of the low-frequency body wave microtremor is centered above the location of the oil reservoir. Two possible explanations for the deep microtremor are elastic body-wave scattering due to the impedance contrast of the structural trap, and viscoelastic scattering due to poroelastic effects in the partially saturated reservoir.

A case study on receiver-clamping quality assessment from the seismic-interferometry processing of downhole seismic noise recordings

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. B195-B203
Author(s):  
Sergey Yaskevich ◽  
Anton A. Duchkov ◽  
Artem Myasnikov
Keyword(s):  
Seismic Noise ◽  
Ambient Noise ◽  
Body Wave ◽  
Wave Spectrum ◽  
Microseismic Monitoring ◽  
Seismic Interferometry ◽  
Receiver Array ◽  
Downhole Tool ◽  
Direct Body

For downhole microseismic monitoring of hydraulic fracturing, the acquisition is performed using a set of three-component (3C) seismic receivers attached firmly to the borehole wall by a clamping mechanism. Such an acquisition cannot be repeated, and it is focused on recording weak signals. Thus, proper installation of the receivers is especially crucial for microseismic applications. We have developed a case study of using a seismic-interferometry approach for assessing the receiver’s installation quality from ambient-noise records. Crosscorrelation of one vertical receiver noise records with the others allows us to retrieve the direct body wave propagating along the receiver array. Our observations indicate that the inability to retrieve the direct body wave is an indicator of clamping issues. Our case study does not support the emergence-frequency hypothesis reported in the literature (that higher frequencies present in the retrieved body-wave spectrum imply better clamping quality). Another conclusion is that seismic-interferometry processing provides a stable assessment of the clamping quality only for the vertical receivers. Thus, one gets only partial diagnostics of the clamping quality for the 3C downhole tool. This is important because the horizontal components may be affected more by the clamping issues compared with the vertical components. The overall conclusion is that seismic-interferometry processing of noise records is recommended for the assessment of the downhole receiver installation prior to microseismic monitoring. It does not provide complete diagnostics but comes for free (does not need any additional technological operations or extra time).

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