SISMA: Workshop finale
ASI, 4 maggio 2011
Il Progetto Progetto SISMA:
razionale, attività e principali risultati
Roberto Sabadini
Università degli Studi di Milano
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA new approach towards the understanding of
earthquake generation and seismic hazard mitigation builds
over three major concepts:
taking advantage of the new generation of DINSAR and GPS deformation data at
the Earth’s surface in conjunction with seismic flow monitoring
which in turn allows us
building an integrated geophysical, geodetic and seismological scheme to disclose
stress build up within the gouge of sesmic active faults for a deterministic
approach of earthquake cycle description
which in turn allows us
overcoming the obvious shortcomings of the old approach to seismic hazard
mitigation based on a purely probabilistic approach
SISMA: Workshop finale
ASI, 4 maggio 2011
Acquisition of the historical
SAR images of the area and
request to running Missions
(e.g. Cosmo Skymed) to
planning new observations.
Establishment of a local
network of GPS Receiver
set uo on monumented sites,
co-located with proper CAT
GPS data processing
to retrieve
continuously updated
deformation and
velocity maps
Formalized analysis
of seismicity update
Restrained areas
For SAR and GPS
Geophysical
Forward Modelling
of stress build up
in the fault gouge
Evaluation of seismic hazard
SAR data processing
to retrieve
continuously updated
deformation and
velocity maps
Permanent
GPS
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
stima deformazione: TIN vs Poligoni (da ZS9)
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
SISMA: Workshop finale
ASI, 4 maggio 2011
CN
algorithm
Northern Region, Mo=5.4
6.5
6.5
1965
1965
1975
1975
5.4
5.66.0 5.55.65.5
5.8
5.8 6.0 5.55.5
5.4
1985
1985
5.8
5.8
6.0
1995
1995
2005
2005
2015
Central Region, Mo=5.6
1955
1955
1965
1965
5.7
6.0 5.7
6.5
6.0
6.5
1975
1975
1985
1985
1995
5.8
5.8 6.0
5.8
5.8 6.0
5.7
6.0 5.7
6.3
1995
2005
2005
2015
1955
1955
Times of Increased
Probability for the
occurrence of
events with
M>Mo within the
monitored regions
Southern Region, Mo=5.6
1965
1965
6.5
6.5
1975
1975
5.7
5.7
1985
1995
1985
1995
2005
2005
2015
M8S
algorithm
Monitored region
M5.5+
M6.0+
M6.5+
Alerted region
SISMA: Workshop finale
ASI, 4 maggio 2011
Geodetic and seismic
integration: IBAY map
Red =
geodetic anomalies plus
seismic alert
Green = neither geodetic anomalies
nor seismic alert
Yellow = geodetic anomalies
Orange = seismic alert
The numbers in the red zones give the
relative alert value.
SISMA: Workshop finale
ASI, 4 maggio 2011
Synthetic seismograms
Ground motion
scenarios
at local scale
Detailed scenarios of ground
motion, including site effects
(2D sections describing the
mechanical properties
of the sites), are defined
at the local scale
for the alerted faults.
Spectral amplifications
2D laterally heterogeneous
local profile
Local ground shaking
scenario for the Gubbio site
SISMA: Workshop finale
ASI, 4 maggio 2011
Conclusions
Although the seismic classification of the Italian territory has been
recently revised, the evaluation of seismic hazard continue to be
based on the traditional probabilistic approach, i.e. on the
probabilistic analysis of earthquake catalogue and of ground motion
information, retrieved by macroseismic observations and
instrumental recordings, that may lead to severe underestimations of
seismic hazard.
Recently this approach showed its limitation in providing a reliable
seismic hazard assessment, possibly due to the insufficient
information about historical seismicity, which can introduce relevant
errors in the purely statistical approach mainly based on the seismic
history.