SISMASeismic Information System for

Monitoring and Alert

Galileian PlusDipartimento di Scienze della Terra, Università di Milano, Italy

Politecnico di Milano, ItalyDipartimento di Scienze della Terra, Università di Trieste, Italy

Agenzia Spaziale Italiana, Sezione Osservazione della Terra

Università di Milano

Coupling geophysical modelling and geodesy to

unravel the physics of active faults

SISMA: a new approach towards the understanding SISMA: a new approach towards the understanding of earthquake generation and seismic hazard of earthquake generation and seismic hazard

mitigation. It builds over three major concepts:mitigation. It 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 allow us

- building an integrated geophysical, geodetic and seismological scheme to disclose stress build up within the gouge of seismic 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 Overall Schema

1°

level

2°

level

3°

level

Restrained areasfor GPS and SAR

Establishment of a local network of GPS ReceiversFor geodynamic purpose

NRT GeophysicalForward modeling

PermanentGPS

Seismicity Analysis

Evaluation of seismic hazard

Near Real Time GPSprocessing to retrievecontinuously updated

deformation and velocity maps

Acquisition of the historicalSAR images of the area.

Near Real Time SARData processing to

retrieve continuously updated deformation

• Maps of alerted areas, prone to earthquake events with given magnitude, will be obtained through comparison of non-EO information, provided by seismological data analysis, and taking into account results provided by Geophysical Modeling based on EO information;

• EO observations, consisting of GPS and DinSAR images, will permit to draw deformation maps on the surface;

• Stress maps at the depth of the active faults will be obtained through integration of EO geodetic information into Geophysical Forward Modeling.

EO Data in Near-Real-Time Applications

•

DinSARGPS

GeophysicalModeling

Strain-rate and stress mapsat local and national scale

NRT applicationNRT applicationin alerted areasin alerted areas

Which is the contribution of Earth Observations?Which is the contribution of Earth Observations?

Inter- and pre-seismic phases: monitoring of surface deformation, which is a possible indicator of stress build up on faults

Co-seismic phase: improves the understanding of the process taking place along the fault plane and permits the estimation of the interactions between the stress field (modified after the seismic event) and the nearby faults.

Post-seismic phase: monitoring possible phenomena (e.g. after-slip, post-seismic relaxation) that may affect the stress field in the lithosphere

Three seismogenic zones,

Friuli-Venezia Giulia

Umbria-Marche

Pollino (Calabria)

are test sites for SISMA

These active seismogenic zones are embedded within the diffuse plate boundary between Africa

and Eurasia, in the central Mediterranean

Africa-Eurasia relative motion

from paleomagnetic

data (NUVEL-1A)

Seismicity (Ms, NEIC 1903-1999) and calculated seismic strain

rate

Comparison between predicted crust and lithosphere deformation patterns and GPS data to verify the feasibility of seismic hazard mitigation: baseline

variations

GPS DATA

Marotta, A. M. et al., JGR 2004 – Combined effects of tectonics and glacial isostatic adjustment on intraplate deformation in central and northern Europe: Application to Geodetic baseline analysis.

Horizontal principal strain rate tensor

Model B:active convergence

+subduction forces in the Hellenic (deep

slab) and Calabrian arcs

Jimenez-Munt, I. et al., (2003) Active deformation in the Mediterranean from Gibraltar to Anatolia inferred from numerical modeling and Geodetic and seismological data

Updated to March 1 2007Updated to March 1 2007

CNalgorithmTimes of Increased Times of Increased Probability for the Probability for the occurrence of occurrence of events with M>Mo events with M>Mo within the within the monitored regionsmonitored regionsNorthern Region, M o=5.4

6 .5 5 .4 5 .8 6 .0

1965 1975 1985 1995 2005

5 .5 5 .6 5 .5

Central Region, M o=5.65 .86 .0 6 .5

5 .76 .0

1955 1965 1975 1985 1995 2005

5 .7

Southern Region, M o=5.65 .86 .0 6 .55 .8

1955 1965 1975 1985 1995 2005

5 .7

M6.5 M5.5M6.0

Monitored region

Alerted region

2003.5-2004

2004-2004.5

2004.5-2005

Events with Mmax 5.5 occurred since July 2003

M8S algorithm

((Peresan al., Earth Sci. RevPeresan al., Earth Sci. Rev.. 200 20055))2006.5-

2007

Methodology for detecting the movements during the co-seismic phases in earthquake prone areas

(Crippa B. et al., 2006).

Surface deformation obtained by geophysical inverse modeling (a) and

DInSAR analysis (b). (c) misfit between

prediction and observation

m

(a) (b)

(c)

Our preliminary results confirm the benefits coming

from the usage of Earth Observation data to

improve the capability of monitoring active

faults in Near Real Time: an important

step toward the mitigation of seismic hazard