Determination of surface-wave phase velocities by zeros of Aki's spectrum of active-source records: Application to the dense array in Tongzhou, China.
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| Title: | Determination of surface-wave phase velocities by zeros of Aki's spectrum of active-source records: Application to the dense array in Tongzhou, China. |
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| Authors: | Qinghua Liu1,2, Laiyu Lu1 laiyulu@cea-igp.ac.cn, Tongwei Qin1, Lijun Chang1 |
| Source: | Earthquake Science. Jun2025, Vol. 38 Issue 3, p218-233. 16p. |
| Subject Terms: | *Phase velocity, *Rayleigh waves, *Seismograms, *Seismic wave velocity, *Bessel functions, *Surface waves (Fluids), *Spectrum analysis |
| Geographic Terms: | Beijing (China), China |
| Abstract: | The spatial autocorrelation (SPAC) (also known as the Aki's spectral method) of ambient seismic noise has been widely adopted in surface wave phase velocity extraction. In two-dimensional cases, the surface wave velocity can be calculated by fitting the SPAC coefficients with the zero-order Bessel function of the first kind or using the zeros of the Aki's spectrum. This method has also been extended to active-source records. This study examined the application of the zeros of Aki's spectra on active-source records using theoretical analysis and numerical simulation. We show that the zeros of the Aki's spectrum should be associated with the zeros of the cosine function instead of the zeros of the zero-order Bessel function when extracting the phase velocity of the surface wave, considering the data acquisition and processing of the active-source records. The proposed method was then applied to the active-source data from methane explosion experiments collected using a dense array in Tongzhou, the subcenter of Beijing, for extracting the phase velocity of Rayleigh wave. The extracted dispersion curves were integrated with those obtained by beamforming the ambient noise to yield broadband dispersion curves at 0.3--6 Hz. This provides insightful results at high frequencies, at which less information can be obtained through the passive-source beamforming. The combing phase velocities from active-source with those obtained from ambient noise provide a better constrain on the shallow structure. Based on the combined fundamental mode dispersion curves at 28 excitation points, the S-wave velocity structure below the dense array is obtained by depth inversion. Due to the constraints imposed by the high-frequency information from active source, the estimated vS30 are more reliable and can be used to the site classification. [ABSTRACT FROM AUTHOR] |
| Database: | Energy & Power Source |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
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| Header | DbId: enr DbLabel: Energy & Power Source An: 184851333 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Determination of surface-wave phase velocities by zeros of Aki's spectrum of active-source records: Application to the dense array in Tongzhou, China. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Qinghua+Liu%22">Qinghua Liu</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Laiyu+Lu%22">Laiyu Lu</searchLink><relatesTo>1</relatesTo><i> laiyulu@cea-igp.ac.cn</i><br /><searchLink fieldCode="AR" term="%22Tongwei+Qin%22">Tongwei Qin</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Lijun+Chang%22">Lijun Chang</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Earthquake+Science%22">Earthquake Science</searchLink>. Jun2025, Vol. 38 Issue 3, p218-233. 16p. – Name: Subject Label: Subject Terms Group: Su Data: *<searchLink fieldCode="DE" term="%22Phase+velocity%22">Phase velocity</searchLink><br />*<searchLink fieldCode="DE" term="%22Rayleigh+waves%22">Rayleigh waves</searchLink><br />*<searchLink fieldCode="DE" term="%22Seismograms%22">Seismograms</searchLink><br />*<searchLink fieldCode="DE" term="%22Seismic+wave+velocity%22">Seismic wave velocity</searchLink><br />*<searchLink fieldCode="DE" term="%22Bessel+functions%22">Bessel functions</searchLink><br />*<searchLink fieldCode="DE" term="%22Surface+waves+%28Fluids%29%22">Surface waves (Fluids)</searchLink><br />*<searchLink fieldCode="DE" term="%22Spectrum+analysis%22">Spectrum analysis</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Beijing+%28China%29%22">Beijing (China)</searchLink><br /><searchLink fieldCode="DE" term="%22China%22">China</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: The spatial autocorrelation (SPAC) (also known as the Aki's spectral method) of ambient seismic noise has been widely adopted in surface wave phase velocity extraction. In two-dimensional cases, the surface wave velocity can be calculated by fitting the SPAC coefficients with the zero-order Bessel function of the first kind or using the zeros of the Aki's spectrum. This method has also been extended to active-source records. This study examined the application of the zeros of Aki's spectra on active-source records using theoretical analysis and numerical simulation. We show that the zeros of the Aki's spectrum should be associated with the zeros of the cosine function instead of the zeros of the zero-order Bessel function when extracting the phase velocity of the surface wave, considering the data acquisition and processing of the active-source records. The proposed method was then applied to the active-source data from methane explosion experiments collected using a dense array in Tongzhou, the subcenter of Beijing, for extracting the phase velocity of Rayleigh wave. The extracted dispersion curves were integrated with those obtained by beamforming the ambient noise to yield broadband dispersion curves at 0.3--6 Hz. This provides insightful results at high frequencies, at which less information can be obtained through the passive-source beamforming. The combing phase velocities from active-source with those obtained from ambient noise provide a better constrain on the shallow structure. Based on the combined fundamental mode dispersion curves at 28 excitation points, the S-wave velocity structure below the dense array is obtained by depth inversion. Due to the constraints imposed by the high-frequency information from active source, the estimated vS30 are more reliable and can be used to the site classification. [ABSTRACT FROM AUTHOR] |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.eqs.2025.01.005 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 16 StartPage: 218 Subjects: – SubjectFull: Phase velocity Type: general – SubjectFull: Rayleigh waves Type: general – SubjectFull: Seismograms Type: general – SubjectFull: Seismic wave velocity Type: general – SubjectFull: Bessel functions Type: general – SubjectFull: Surface waves (Fluids) Type: general – SubjectFull: Spectrum analysis Type: general – SubjectFull: Beijing (China) Type: general – SubjectFull: China Type: general Titles: – TitleFull: Determination of surface-wave phase velocities by zeros of Aki's spectrum of active-source records: Application to the dense array in Tongzhou, China. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Qinghua Liu – PersonEntity: Name: NameFull: Laiyu Lu – PersonEntity: Name: NameFull: Tongwei Qin – PersonEntity: Name: NameFull: Lijun Chang IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2025 Type: published Y: 2025 Identifiers: – Type: issn-print Value: 16744519 Numbering: – Type: volume Value: 38 – Type: issue Value: 3 Titles: – TitleFull: Earthquake Science Type: main |
| ResultId | 1 |
