Publication Date:
2012-02-03
Description:
A station (FAGN) installed on a segment of the fault
system that generated the April 2009 L’Aquila earthquakes
shows larger ground motions compared to nearby stations.
Spectral ratios using 304 earthquakes result in a station
amplification significantly varying event by event in the
frequency band 1–8 Hz. The resulting pattern of amplitude
dependence on causative earthquake location reveals that the
strongest (up to a factor of 10) amplifications occur for tightly
clustered aftershocks aligned with the fault dip beneath
FAGN thus indicating a fault‐guided effect. Fault models are
investigated in a grid‐search approach by varying velocity, Q,
width and depth of the fault zone. Although the problem
solution is not unique and there are strong trade‐offs among
the model parameters, constraints from observations yield a
deep trapping structure model where the most likely values of
velocity reduction, Q and damage zone width are 25%, 20,
and 280 m, respectively.
Description:
Published
Description:
L24305
Description:
3.1. Fisica dei terremoti
Description:
4.1. Metodologie sismologiche per l'ingegneria sismica
Description:
JCR Journal
Description:
reserved
Keywords:
L'Aquila earthquake
;
fault zone
;
trapped waves
;
site amplification
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
;
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
;
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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