Publication Date:
2017-04-04
Description:
The West side of lake of Garda, in Northern Italy, was struck by a ML=5.2 earthquake on
November 24, 2004. The felt area is rather large (from Venice to Milan) and the damaged area
consists of 66 municipalities, with a number of homeless of about 2200 and estimated direct
damages of 215 millions of euros. Most of the damaged structures are old masonry buildings and
churches, while there were almost no damage to reinforced concrete structures. The observed
distribution of macroseismic intensity shows a strong azimuthal dependence, with high intensity
level in a 10x10 km2 area located SW to the epicentre and rather large dispersion of values
(ranging from V to VII-VIII) in the first 10 km epicentral distance.
Taking into account the vulnerability level of the damaged structures and the features of the
geological formations, we tried to explain the observed damage distribution in terms of finite fault
properties of the source, despite the moderate magnitude of the event.
Thus we hypothesised a fault geometry from seismotectonic considerations and we simulated the
event by a high frequency simulation technique (Deterministic Stochastic Method, DSM). The
synthetic ground motion parameters were converted into intensity values by empirical
relationships and local geological conditions were considered to explain some discrepancies
between simulated and observed intensities. It was possible to adequately reproduce both the
observed distribution of macroseismic intensity and the ground motion recorded by an
accelerometric station located at about 13 km epicentral distance.
Description:
Unpublished
Description:
Geneva, Switzerland
Description:
open
Keywords:
Damage
;
Seismology
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Conference paper
