Publication Date:
2018-03-14
Description:
In the last decades, the use of microtremors to assess linear site effects has received a significant
attention. Various authors demonstrate the reliability of ambient noise processing techniques to assess
the relative amplification generally between distant sites (〉1-10 km) in the low frequency range (〈1
Hz). In this study we attempt to evaluate the validity of such an approach at the scale of an industrial
facility (≈300 m) and up to high frequency (≈10 Hz) on two sites: an industrial site located across a
small sedimentary basin in the low-to-moderate seismicity context of Southeastern France (Provence)
and another sedimentary basin in the seismically active island of Cephalonia in Greece. On both sites,
transfer functions relative to a rock reference deduced from microtremors (SSRn) are compared to
those obtained from earthquake recordings with the classical Standard Spectral Ratio (SSR) approach.
We find a good agreement between both approaches until intermediate frequencies. We thus propose
an approach based on microtremor recordings and on one neighboring available SSR computed for a
station located inside the basin (SSRh). This new approach seems reliable to assess the spatial
variability of the site amplification up to high frequency (microzonation). The upper frequency limit
for both noise approaches (SSRn and SSRh) is discussed according to the inter-station distance and to
the stations geological context.
Description:
Published
Description:
Taipei, Taiwan
Description:
4T. Sismologia, geofisica e geologia per l'ingegneria sismica
Keywords:
site effect
;
ambient noise processing technique
;
spectral ratio
;
low-tomoderate seismicity context
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Extended abstract
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