Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/12282
Authors: Perron, Vincent* 
Gélis, Céline* 
Froment, Bérénice* 
Hollender, Fabrice* 
Bard, Pierre-Yves* 
Cultrera, Giovanna* 
Cushing, Edward Marc* 
Title: Can broad-band earthquake site responses be predicted by the ambient noise spectral ratio? Insight from observations at two sedimentary basins
Journal: Geophysical Journal International 
Series/Report no.: /215 (2018)
Issue Date: 2018
DOI: 10.1093/gji/ggy355
Keywords: Earthquake ground motions
Site effects
Seismic noise
Spectral ratio
Subject Classification04.06. Seismology 
Abstract: Site-effect assessments performed through earthquake-based approaches, such as the standard spectral ratio (SSR), require good quality records of numerous earthquakes. In contrast, the use of ambient noise appears to be an attractive solution for ease and rapid computation of site responses with sufficient spatial resolution (microzonation), especially in low seismicity areas. Two main approaches are tested here: the horizontal-to-vertical spectral ratio (HVSR) and the noise-based SSR (SSRn). The HVSR uses the relative amplitude of the horizontal and vertical components of the ambient noise. Instead, the SSRn defines the spectral ratio between the seismic noise recorded simultaneously at a site and at a rock reference station, similar to earthquake-based SSR. While the HVSR is currently used in hundreds of site-specific studies, the SSRn approach has been gradually abandoned since the 1990s. In this study, we compare the results obtain from these two approaches with those of earthquake-based SSR. This comparison is carried out for two sedimentary basins, in Provence (southeastern France) and in Argostoli (western Greece). In agreement with the literature, the HVSR does not provide more than the fundamental resonance frequency of the site (f0). The SSRn leads to overestimation of the SSR amplification factors for frequencies higher than the minimal f0 of the basin (f0min). This discrepancy between SSRn and SSR is discussed, and appears to be mainly dependent on the local geological configuration. We thus introduce the hybrid standard spectral ratio (SSRh) approach, which aims to improve upon the SSRn by adding an intermediate station inside the basin for which the SSR is known. This station is used in turn as a local reference inside the basin for the SSRn computation. The SSRh provides site transfer functions very similar to those of the SSR, in a broad frequency range. Based on these results, the SSRn (or SSRh) should be further tested and should receive renewed attention for microzonation inside sedimentary basins.
Appears in Collections:Article published / in press

Files in This Item:
File Description SizeFormat
Perron_etal_GJI2018.pdf3.77 MBAdobe PDFView/Open
Show full item record

WEB OF SCIENCETM
Citations

10
Last Week
0
Last month
0
checked on Feb 10, 2021

Page view(s)

69
Last Week
0
Last month
2
checked on Jul 29, 2021

Download(s)

18
checked on Jul 29, 2021

Google ScholarTM

Check

Altmetric