Hybrid Broadband Ground-Motion Simulations: Combining Long-Period Deterministic Synthetics with High-Frequency Multiple S-to-S Backscattering

Handle URI:
http://hdl.handle.net/10754/555744
Title:
Hybrid Broadband Ground-Motion Simulations: Combining Long-Period Deterministic Synthetics with High-Frequency Multiple S-to-S Backscattering
Authors:
Mai, Paul Martin ( 0000-0002-9744-4964 ) ; Imperatori, W.; Olsen, K. B.
Abstract:
We present a new approach for computing broadband (0-10 Hz) synthetic seismograms by combining high-frequency (HF) scattering with low-frequency (LF) deterministic seismograms, considering finite-fault earthquake rupture models embedded in 3D earth structure. Site-specific HF-scattering Green's functions for a heterogeneous medium with uniformly distributed random isotropic scatterers are convolved with a source-time function that characterizes the temporal evolution of the rupture process. These scatterograms are then reconciled with the LF-deterministic waveforms using a frequency-domain optimization to match both amplitude and phase spectra around the target intersection frequency. The scattering parameters of the medium, scattering attenuation ηs, intrinsic attenuation ηi, and site-kappa, as well as frequency-dependent attenuation, determine waveform and spectral character of the HF-synthetics and thus affect the hybrid broadband seismograms. Applying our methodology to the 1994 Northridge earthquake and validating against near-field recordings at 24 sites, we find that our technique provides realistic broadband waveforms and consistently reproduces LF ground-motion intensities for two independent source descriptions. The least biased results, compared to recorded strong-motion data, are obtained after applying a frequency-dependent site-amplification factor to the broadband simulations. This innovative hybrid ground-motion simulation approach, applicable to any arbitrarily complex earthquake source model, is well suited for seismic hazard analysis and ground-motion estimation.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Hybrid Broadband Ground-Motion Simulations: Combining Long-Period Deterministic Synthetics with High-Frequency Multiple S-to-S Backscattering 2010, 100 (5A):2124 Bulletin of the Seismological Society of America
Journal:
Bulletin of the Seismological Society of America
Issue Date:
20-Sep-2010
DOI:
10.1785/0120080194
Type:
Article
ISSN:
0037-1106
Additional Links:
http://www.bssaonline.org/cgi/doi/10.1785/0120080194
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorMai, Paul Martinen
dc.contributor.authorImperatori, W.en
dc.contributor.authorOlsen, K. B.en
dc.date.accessioned2015-05-26T06:59:57Zen
dc.date.available2015-05-26T06:59:57Zen
dc.date.issued2010-09-20en
dc.identifier.citationHybrid Broadband Ground-Motion Simulations: Combining Long-Period Deterministic Synthetics with High-Frequency Multiple S-to-S Backscattering 2010, 100 (5A):2124 Bulletin of the Seismological Society of Americaen
dc.identifier.issn0037-1106en
dc.identifier.doi10.1785/0120080194en
dc.identifier.urihttp://hdl.handle.net/10754/555744en
dc.description.abstractWe present a new approach for computing broadband (0-10 Hz) synthetic seismograms by combining high-frequency (HF) scattering with low-frequency (LF) deterministic seismograms, considering finite-fault earthquake rupture models embedded in 3D earth structure. Site-specific HF-scattering Green's functions for a heterogeneous medium with uniformly distributed random isotropic scatterers are convolved with a source-time function that characterizes the temporal evolution of the rupture process. These scatterograms are then reconciled with the LF-deterministic waveforms using a frequency-domain optimization to match both amplitude and phase spectra around the target intersection frequency. The scattering parameters of the medium, scattering attenuation ηs, intrinsic attenuation ηi, and site-kappa, as well as frequency-dependent attenuation, determine waveform and spectral character of the HF-synthetics and thus affect the hybrid broadband seismograms. Applying our methodology to the 1994 Northridge earthquake and validating against near-field recordings at 24 sites, we find that our technique provides realistic broadband waveforms and consistently reproduces LF ground-motion intensities for two independent source descriptions. The least biased results, compared to recorded strong-motion data, are obtained after applying a frequency-dependent site-amplification factor to the broadband simulations. This innovative hybrid ground-motion simulation approach, applicable to any arbitrarily complex earthquake source model, is well suited for seismic hazard analysis and ground-motion estimation.en
dc.relation.urlhttp://www.bssaonline.org/cgi/doi/10.1785/0120080194en
dc.rightsArchived with thanks to Bulletin of the Seismological Society of America © 2015 by the Seismological Society of Americaen
dc.titleHybrid Broadband Ground-Motion Simulations: Combining Long-Period Deterministic Synthetics with High-Frequency Multiple S-to-S Backscatteringen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalBulletin of the Seismological Society of Americaen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionInstitute of Geophysics, ETH Zurich Sonneggstrasse 5 CH-8092 Zurich, Switzerlanden
dc.contributor.institutionDepartment of Geological Sciences San Diego State University San Diego, California 92182-1020en
kaust.authorMai, Paul Martinen
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