1. Application of Simulated Data: The Mt Etna Case Langer, Tusa, Scarfì, Azarro, Varini*, Zonno… INGV – Oss. Etneo, Catania, Italy CNR-IMATI – Milano, Italy

2. Tectonic & Geological Features Siniscalco et al., 2012

3. Deformation Field Regional Displacement field, see D’Agostino & Selvaggi, 2004 Horizontal Displacement (p. a., in mm) see Gugielmino et al., 2011

4. Seismicity Patterns Etna (2009-2012) © INGV – staff analysts Oss. Etneo, Catania)-

5. Typical Waveforms of Shallow (SEE) and Deeper Etna Events (DEE) E N Z Supferf. Etnean Event (M=3.8, d=5km, z= 1 km) Deeper Etnean Event (M=3.6, d=5km, z= 6 km)

6. The basement of Mt Etna Resistivity profile after Siniscalco et al., 2012. Intermediate resisitivy (several to ca. 60 Ohm.m are indentified as sedimentary substratum, mainly tertiary and quaternary clays)

7. Data Set from Relevant Areas

8. Empirical GMPEs GroupYabc  LogY SEE* PGA (cm s -2 )-0.8050.817-1.9890.372 PGV (cm s -1 )-2.8981.060-1.8290.365 PGD (cm)-4.5801.279-1.6680.382 DEE** PGA (cm s -2 )-0.2980.845-2.0020.372 PGV (cm s -1 )-2.0710.883-1.8130.328 PGD (cm)-3.4740.862-1.5230.345 EEE*** PGA (cm s -2 )-0.2930.809-1.8350.410 PGV (cm s -1 )-2.3220.946-1.7040.347 PGD (cm) -4.0611.003-1.4020.369

9. Empirical Ground Motion Prediction (3<M<4.8) Shallow (z=1km), M=4.3 Deep(z=25),M=4.4

10. The Problem of Direct Extrapolation of empirical GMPEs

11. A Way Out: Complex Extented Source Model (EXSIM)

12. First attempts… Empirical Results for M=3.3 Synthetic Results (EXSIMI) for Standard Input Parameters (M=3.3, z=1 km, L=W=500m, stress =5 bar, Q=30*f 0.7 )

13. Trial Input Parameters (Etna) Q 0 (f < 1Hz)QNQN β S (sup/deep)β M (sup/deep)R -1 R0R0 R -0.5 9090*f 0.7 1.8/3.0 km/s2.4-3.0/3-3.5 km/s0-3535-70>70 km β S = velocity at sourc, β M = velocity of propagation medium (geom. spreading) Mw (5/50 bar)3.3/4.04.3/5.05.3/6.0--/7.0 Length (km)0.882.88.828.0 Width (km)0.441.44.414.0 Etna 1914Etna 9.10.2002 Mw54.8 Stress20 bar Length (km)8.05.6 Width (km)2.51.4 General scaling laws Case studies (superficial)

14. SEE, M=3.3.fmax =5 DEE, M=4 Exsim Synthetic (Hardrock) vs. Empiric

15. SiteThicknessS-VelocityDensityQ Site C5 m100 m/s1700 kg/m 3 10 5 m400 m/s1700 kg/m 3 20 Site B20 m400 m/s1700 kg/m 3 15 Volc. Rock100 m2000 m/s2000 kg/m 3 30 LayerThicknessS-velocityDensityQ Shale100 m600 m/s1800 kg/m 3 20 Cons. Shale500 m1500 m/s2100 kg/m 3 70 Cons. Shale300 m1700 m/s2200 kg/m 3 100 Limestone5000 m2600 m/s2500 kg/m 3 150 Basement  3500 m/s2800 kg/m 3  Generalized Velocity Models

16. Case Mt Etna, 1914. M=5, I =IX I (Observed) I (from Housner Intensity: I = 1.41 ln (Ih)+7.98 Exsim, Site C Exsim, Site B Exsim, Hardrock

17. Case Mt Etna 1914 (M ca. 5, I = IX)

18. I (Observed) Case Etna, 1914, (ctd) Log PGA (gal), syn Log PGV (cm/s), syn.

19. Etna 29.10.2002Etna 29.10.2002 (EXSIM) IoVIII8 PGA 18 km15 gal8…15 gal PGV 4.5 cm/s0.6..1.1 cm/s From Milana et al., 2008

20. Exsim simulation for M=6 DEE event: Catania /Acireale 1818

21. “Extrapolation” via synthetic simulation

22. Conclusion Distinction of two dynamic regimes Different GMPE for shallow and deeper events Empirical GMPEs should not extrapolated to larger events Small events may be used for calibrating input pameters in synthetic modelling Discrepances between empirical GMPEs for large and small earthquakes can be explained by using extended sources.