1. Zadonina E.O. (1), Caldeira B. (1,2), Bezzeghoud M. (1,2), Borges J.F. (1,2) (1) Centro de Geofísica de Évora (2) Departamento de Física, Universidade de Évora

2. Study of a recent large earthquake Determine a slip model by inverting teleseismic body waves Confront the obtained model to various independent datasets

3. 12 May 2008 – Wenchuan Earthquake Mw 7.9 (China) Occurred on the boundary between Longmen Shan and Sichuan basin (31.1 ˚ N, 103.3 ˚ E ) at the 19 km depth Claimed 69,000 lives

4. Wenchuan Beichuan Anaxian Zipingpu Dam Google Earth image Wanju et al, 2008 Sichuan basin

5. Preprocessing of teleseismic body waves and determination of source parameters Inversion of teleseismic body-waves with Kikuchi and Kanamori's algorithm to obtain slip distribution Modeling of horizontal displacements and Coulomb stress change Comparison of obtained results with GPS data and aftershocks distribution

8. Time of rupture > 90 s Rise time ~ 30 s

9. Observed Modeled Projection of upper edge of fault plane onto the surface

10. Data about aftershocks was taken for the period of 3 month after the main event 3<Mw<7 3 km<Depth<32 km

11. Stress increase Stress release Δσ с = Δτ - μ ’ Δσ n μ ’ = μ(1 - B)

12. Obtained horizontal surface displacement not in the strict agreement with observed data Changes in static Coulomb stress are consistent with aftershock distribution down to a depth of 7 km Perspective – refining of existing source parameters and slip model; joint inversion of strong motion data and InSAR data

13. Synthesize high-frequency near-fault waveforms produced by hypothetical earthquake with certain parameters Numerically estimate the influence of some of the used parameters – source time function, geometry of a fault plain, variations in velocity model, rupture velocity - on the waveforms Use obtained knowledge in synthesis of waveforms of real event – The Alum Rock earthquake occurred on October 30, 2007 using the existing slip model of the event and Community Velocity Model SCEC CVM-H 6.2

14. 2D/3D elastic finite-difference wave propagation code E3D based on the elastodynamic formulation of the wave equation on a staggered grid Misfit Criteria for Quantitative Comparison of Seismograms by Miriam Kristeková et al.

15. October 30, 2007 37,43 N, 121,78 W Mw 5.6 9.2 km depth Strike: 323˚ Dip: 87 ˚ Rake: -180 ˚ Slip distribution by Margaret Hellweg et al.