Progetto S5 – Test sites per il monitoraggio multidisciplinare di dettaglio
WP2.4 – Ground deformation pattern of the Calabro-Peloritan area
and the Messina Strait from GPS networks and terrestrial data
Mattia M.1, Aloisi M.1, Anzidei M.2, Bruno V.1,
Cannavò F.1, Cheloni D.2, D’Agostino N.2,
Mastrolembo B.3, Palano M.1, Serpelloni E.2
INGV - Sezione di Catania
2) INGV - Centro Nazionale Terremoti, Roma
3) Dipartimento di Fisica, Università di Bologna
GOALS
Velocity and strain rate field across the Messina Straits and the
Calabrian Arc from the analysis of periodical and continuous GPS
data.
Elastic block modelling, inter-seismic strain loading and deep
geometry of the 1908 Messina fault.
Analysis of triangulation data for the estimates of the strain rates in
the Messina Straits and the interseismic tectonic loading on the
fault responsible for the 1908 Messina earthquake.
Modelling of the source responsible for the December 28, 1908
earthquake, by using a numerical approach (i.e. finite element).
GPS
GPSstrain-rate
velocity
Reference Frame: EURASIA
Observation Time
1996.00 – 2008.21
Strain-rate computed as
described in Haines and
Holt, 1993.
Mattia et al., 2009,
Tectonophysics
Ground deformation modeling
GPS velocity field was modeled by using 3
different approaches:
1) vectorial decomposition of velocities
measured across main fault system.
2) analytical inversion of residual velocity
field computed taking into account the
motion of the African plate with respect to
the Eurasian plate.
3) analytical inversion of velocity field
taking into account the GPS baselines
and their length variations.
Eurasia fixed
GPS velocities (with 95%
error ellipses) in a Eurasiafixed reference frame. We
use only stations with > 2.5
yrs time-span.
~3 mm/yr
~6.5 mm/yr
ApΩEu
4.0 mm/yr
KAl
NuΩEu
4.9 mm/yr
~30°
~4.5 mm/yr
1.6 mm/yr
We use rectangular ,
uniform-slip, dislocations
embedded in an elastic,
homogeneous and
isotropic half-space and a
constrained, non-linear
optimization algorithm, to
solve for the best fit
rectangular fault geometry
and fault slip rate.
Assuming a quasi 2D
model, we constrain the
fault strike, base on the
estimated strain-rate field,
and explore all other
parameters.
3.5 mm/yr
7.6 km
30°
Uncertainties (68%
confidence level) have
been estimated using a
bootstrap approach.
Shear strain rates (nanostrain/yr) and
Orientation of the most extensional strain (degrees)
g1
g2
sg1
sg2
q
sq
-23.37
-113.88
48.71
54.96
140.79
44.89
Shear strain rates plottati come gamma
totale nella direzione di massima estensione.
Daniele Cheloni, Tesi Dottorato Univ. Bologna
Ground deformation modeling of leveling data (Loperfido, 1909)
Sensitivity test
CONCLUSIONS
The main objectives of the WP have been achieved.
The FEM modelling of the source responsible for the December 28, 1908
earthquake is still in progress.
Thank you!