Publication Date:
2017-04-04
Description:
Based only on weak-motion data, we carried out a combined study on region-specific source
scaling and crustal attenuation in the Central Apennines (Italy). Our goal was to obtain a
reappraisal of the existing predictive relationships for the ground motion, and to test them
against the strong-motion data [peak ground acceleration (PGA), peak ground velocity (PGV)
and spectral acceleration (SA)] gathered during the Mw 6.15 L’Aquila earthquake (2009 April
6, 01:32 UTC). The L’Aquila main shockwas not part of the predictive study, and the validation
test was an extrapolation to one magnitude unit above the largest earthquake of the calibration
data set.
The regional attenuation was determined through a set of regressions on a data set of
12 777 high-quality, high-gain waveforms with excellent S/N ratios (4259 vertical and 8518
horizontal time histories). Seismograms were selected from the recordings of 170 foreshocks
and aftershocks of the sequence (the complete set of all earthquakes with ML ≥ 3.0, from
2008 October 1 to 2010 May 10). All waveforms were downloaded from the ISIDe web
page (http://iside.rm.ingv.it/iside/standard/index.jsp), a web site maintained by the Istituto
Nazionale di Geofisica e Vulcanologia (INGV).
Weak-motion data were used to obtain a moment tensor solution, as well as a coda-based
moment-rate source spectrum, for each one of the 170 events of the L’Aquila sequence (2.8 ≤ Mw ≤ 6.15). Source spectra were used to verify the good agreement with the source scaling of
the Colfiorito seismic sequence of 1997–1998 recently described by Malagnini et al. (2008).
Finally, results on source excitation and crustal attenuationwere used to produce the absolute
site terms for the 23 stations located within ∼80 km of the epicentral area. The complete set
of spectral corrections (crustal attenuation and absolute site effects) was used to implement
a fast and accurate tool for the automatic computation of moment magnitudes in the Central
Apennines.
Description:
Published
Description:
325-337
Description:
4.1. Metodologie sismologiche per l'ingegneria sismica
Description:
JCR Journal
Description:
reserved
Keywords:
Earthquake ground motions
;
central Italy
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
