Publication Date:
2017-04-04
Description:
The goals of this work are to review the Northern-Italy ground-motion
prediction equations (GMPEs) for amplitude parameters and to propose new GMPEs
for frequency content and duration parameters. Approximately 10,000 weak and
strong waveforms have been collected merging information from different neighboring
regional seismic networks operating in the last 30 yr throughout Northern Italy.
New ground-motion models, calibrated for epicentral distances ≤100 km and for both
local (ML) and moment magnitude (Mw), have been developed starting from a high
quality dataset (624 waveforms) that consists of 82 selected earthquakes with ML and
Mw up to 6.3 and 6.5, respectively. The vertical component and the maximum of the
two horizontal components of motion have been considered, for both acceleration
(peak ground horizontal acceleration [PGHA] and peak ground vertical acceleration
[PGVA]) and velocity (peak ground horizontal velocity [PGHV] and peak ground vertical
velocity [PGVV]) data. In order to make comparisons with the most commonly
used prediction equations for the Italian territory (Sabetta and Pugliese, 1996 [hereafter,
SP96] and Ambraseys et al. 2005a,b [hereafter, AM05]) the coefficients for acceleration
response spectra (spectral horizontal acceleration [SHA] and spectral
vertical acceleration [SVA]) and for pseudovelocity response spectra (pseudospectral
horizontal velocity [PSHV] and pseudospectral vertical velocity [PSVV]) have been
calculated for 12 periods ranging between 0.04 and 2 sec and for 14 periods ranging
between 0.04 and 4 sec, respectively. Finally, empirical relations for Arias intensities
(IA), Housner intensities (IH), and strong motion duration (DV) have also been calibrated.
The site classification based on Eurocode (hereafter, EC8) classes has been
used (ENV, 1998, 2002). The coefficients of the models have been determined using
functional forms with an independent magnitude decay rate and applying the random
effects model (Abrahamson and Youngs, 1992; Joyner and Boore, 1993) that allow the
determination of the interevent, interstation, and record-to-record components of variance.
The goodness of fit between observed and predicted values has been evaluated
using the maximum likelihood approach as in Spudich et al. (1999). Comparing
the proposed GMPEs with SP96 and AM05, it is possible to observe a faster decay of
predicted ground motion, in particular for distances greater than 25 km and magnitudes
higher than 5.0. The result is an improvement in fit of about one order of size for
magnitudes spanning from 3.5 to 4.5.
Description:
Published
Description:
1319-1342
Description:
1.1. TTC - Monitoraggio sismico del territorio nazionale
Description:
JCR Journal
Description:
reserved
Keywords:
ground motion prediction equations
;
north italy
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
;
04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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