Ground motion simulations in the Pollino region (Southern Italy) for

Mw 6.4 scenario events

ITIS023 Mercure Basin Fault ITCS038 Remediello-Mormanno Composite sourceDISS reports that the seismogenic potential associated to such faults is Mw 6.4.

Source Model – Mercure Basin Fault

Approximated 1D wave-propagation (ray theory)

Lenght=22km ; Width=13kmStrike, dip, rake= 335° , 60°, -90°Top depth = 1 km Mw=6.4

Slip distribution = Heterogeneous (with 2 main patches of slip)rupture velocity = 0.8 Vs

Spectral attenuation modelR=10km R=50km

Rovelli et al., 1988Cantore et al., 2011 – Irpinia 1<f<30 HzCastro et al., 2004 – Basilicata 2<f<10 Hz

GR=1/RVs= 3.4 km/sκ =0.035 s

DSMSynthetic seismograms are computed through a modified versione of the stochastic method proposed by Boore (1983) for point source model:

• Gaussian noise is modulated with acceleration envelopes, computed solving the rapresentation theorem for an extend source

• The amplitudes are scaled applying a Reference Fourier spectrum, whose parameters (corner frequency and distance from the fault ) are inferred from the modelling of the extend source.

=

X Random Noise

Deterministic Envelope

IFFT (point-source-like Reference Spectrum)

NS

Synthetic Seismogram

Ground motion maps (PGA bedrock)

scenario 1: northwestern rupture propagation

Ground motion maps (PGA bedrock)

scenario 2: bilateral rupture propagation

Ground motion maps (PGA bedrock)

scenario 3: southeastern rupture propagation

Ground motion maps (PGA bedrock)

GMPE scenario: ITA10 mean predictions

Comparioson with empirical GMPEs

Acc. Response Spectra at 2 sites

Mormanno

Lauria

Strong motion data from RAN and INGV stations

INGV stations