Publication Date:
2022-06-09
Description:
Results of geological, geomechanical and seismometric investigations aiming at the
analysis of the seismic response in a carbonate ridge of the Nera River valley (Central Apennines
– Italy) are discussed. Geological and geomechanical surveys were aimed at defining the
stratigraphic and structural setting of the outcropping formations and the jointing conditions of
the rock mass. Velocimetric records of both ambient noise and small-magnitude earthquakes
were analysed in order to identify amplification conditions. The analysis was carried out in the
time domain, through directional energy evaluation, and in the frequency domain, through H/V
spectral ratios and spectral ratios with respect to a reference station. A local amplification factor
was estimated from Housner intensity. The study revealed a significant seismic amplification in a
fault zone. This effect was observed in intensely jointed and mylonitic rock masses, located
inside moderately jointed rock masses, and is the result of specific geometries and significant
impedance contrasts. A map of fault zones prone to amplification of ground motion was
constructed, taking into account the jointing conditions of the rock masses and the structural
setting of the investigated ridge. The study relied on an integrated methodological approach,
which combined the available data under union and intersection criteria.
Description:
Published
Description:
416-449
Description:
JCR Journal
Description:
reserved
Keywords:
jointed rock masses
;
velocimetric records
;
seismic amplification
;
trapped waves
;
Central Italy
;
04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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