Please use this identifier to cite or link to this item:
Authors: Bindi, D.* 
Parolai, S.* 
Cara, F.* 
Di Giulio, G.* 
Ferretti, G.* 
Luzi, L.* 
Monachesi, G.* 
Pacor, F.* 
Rovelli, A.* 
Title: Site Amplifications Observed in the Gubbio Basin, Central Italy: Hints for Lateral Propagation Effects
Journal: Bulletin Of The Seismological Society of America 
Series/Report no.: 2A/99 (2009)
Publisher: Seismological Society of America
Issue Date: Apr-2009
DOI: 10.1785/0120080238
Keywords: site amplification
Subject Classification04. Solid Earth::04.06. Seismology::04.06.04. Ground motion 
Abstract: In this study we investigate the site amplification effects observed in the Gubbio plain, central Italy. The recordings of 140 local earthquakes (1:2 ≤ Ml ≤ 4:7) observed by two linear arrays installed along the longitudinal and perpendicular basin axis are analyzed both in the time and frequency domains to determine the spatial variation of the local site effects in the basin. The time series recorded in the Gubbio plain are characterized by locally generated surface waves, which cause a significant increase in both ground-motion duration and amplitude with respect to a nearby reference station on a rock site. In the middle of the basin where the sedimentary cover is thickest (ca 600 m), the peak ground velocity is amplified on average by a factor of 5 with respect to the reference station installed on rock, and the duration is increased by a factor of about 2. The analyses in the frequency domain show that the spectral energy of the basin-generated waves is mainly distributed over the range 0.4–2 Hz and affects both horizontal and vertical components. The site responses estimated by applying two reference site methods show that the overall shape of the amplification functions is similar for the sites located inside the basin with a difference in the amplification levels, which can reach values as high as 30 in the middle of the valley. Amplifications up to a factor of 10 affect the vertical component of ground motion over a broad frequency range for nearly all basin sites with the maximum amplifications occurring at around 1 Hz. Finally, although the horizontal-to-vertical spectral ratios were found to provide a reliable estimation of the fundamental resonance frequency of the site, they fail to estimate the shape of the site transfer function
Appears in Collections:Article published / in press

Files in This Item:
File Description SizeFormat Existing users please Login
bindi_et_al_Bssa2009_gubbio.pdfMain a2.12 MBAdobe PDF
Show full item record


checked on Jul 9, 2020

Page view(s)

Last Week
Last month
checked on Jul 11, 2020


checked on Jul 11, 2020

Google ScholarTM