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Www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Seismic wave Propagation and Imaging in Complex media: a European.

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Presentation on theme: "Www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Seismic wave Propagation and Imaging in Complex media: a European."— Presentation transcript:

1 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Seismic wave Propagation and Imaging in Complex media: a European network Yilong Qin Early Stage Researcher Host Institution: IPG, Paris Place of Origin: Beijing, China Appointment Time: Jan. 2005 Project: A SPICE synthetic dataset to benchmark global tomographic methods Task Groups: Planetary Scales Cooperation: Universitetet I Oslo, Norway University of Utrecht, Netherlands Yilong Qin Early Stage Researcher Host Institution: IPG, Paris Place of Origin: Beijing, China Appointment Time: Jan. 2005 Project: A SPICE synthetic dataset to benchmark global tomographic methods Task Groups: Planetary Scales Cooperation: Universitetet I Oslo, Norway University of Utrecht, Netherlands

2 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Content Project Scope Benchmark of benchmark Final benchmark Conclusions

3 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Project Scope There is general agreement about the location of long-wavelength structure. But the small-scale features still vary considerably from author to author From The Reference Earth Model Website (http://mahi.ucsd.edu/Gabi/rem.html)

4 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland The benchmark of benchmark Model build Acquisition geometry Computation Synthetic data Inversion results

5 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Model build 1D model (red) and PREM model (black) 3D model (Vs). Depth-independent Large-, medium- and samll-scale anomaly. Model parameters: isotropic Vp, Vs and density, gravity, attenuation 1D reference model and 3D model

6 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Acquisition geometry 27 events 256 receivers Distribution of events and station

7 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Computation 3D Coupling Spectral Elements and Modal Solution (CSEM) (Capdeville et al., ) Z, N-S and E-W velocity component Not consider the effect of ellipticity, crust, topography, ocean and rotation of real Earth. 10500s records

8 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Upper: comparison between CSEM and Normal-mode Lower: Source wavelet (left) and its spectrum (right) ( minimum period 50s)

9 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Synthetic data Comparison seismograms between 1D and 3D model FFC COYC XMAS

10 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Inversion Automated multimode inversion based on time- frequency partition of waveform (Lebedev et al., 2005) Courtesy of S. Lebedev

11 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Inversion results (Sergei Lebedev)

12 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland The final benchmark Acquisition geometry Model build Computation Synthetic data

13 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Distribution of stations and events. Near the location of red beach ball, three events are calculated.

14 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Model build Model parameters : P-wave isotropic average velocity, S- wave isotropic average velocity, Density, quality factor(Qmu), anisotropic parameter for vertically transverse anisotropic (xi, phi and eta) and the orientation of the crystal 1D model 3D variation Crustal model Topography and bathmetry

15 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland 1D Valerie model Anisotropic model (D” layer, upper mantle and transition zone) Six layer (D’’, lower lower mantle, upper lower mantle, transition zone, upper mantle and crust) boundary is 3480.0km, 3780.0km, 4700.0km, 5701.0km, 5971.0km, 6345.0km, 6371.0km.

16 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Comparison of Eigenfrequency for 1D Valerie model and PREM

17 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland P, S and density variation ( release after blind test ) Random part: defined as spherical harmonic component. we have added mixture of adjacent layers over a depth interval of 250km. The deterministic part: medium- and small- scale variation S-wave and density variation are coupled with P-wave variation Crystal with variable orientation of symmetry

18 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Crustal model for Vs Crustal model for density The crust has a significant impact on the observed seismic data but, at the same time, is too thin to be resolved by them. Crustal model (smoothed CRUST2.0) Constant depth=26km

19 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Topography and bathmetry (ETOPO5) The ocean are incorporated in the CSEM by introducing an equivalent load a the ocean floor( Dimitri Komatitsch and Jeroen Tromp, 2002)

20 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Computation Algorithm coupling spectral element method (including the effect of anisotropy, gravity, attenuation, rotation, ocean, ellipticity, topography) Computation time Total hours is about 70000 CPU hours Time step 0.35s, a compromise between numerical dispersion and computation cost. Implementation IPGP (Institut de physique du globe de Paris) IDRIS (Institut du Développement et des Ressources en Informatique Scientifique) CINES (Centre Informatique National de l'Enseignement Supérieur)

21 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Courtesy of Capdeville Coupling Spectral-element method (CSEM) Mesh topography Ocean

22 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Source wavelet An heavis wavelet with frequency up to 0.031Hz (minimum period 32s ) wavelet spectrum

23 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Derivative of source wavelet and the corresponding spectrum

24 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Comparison between normal-mode (black) and CSEM (red for 0.2s of time step, green for 0.4s time step) for minimum period of 32s. Numerical dispersion for maximum period 32s

25 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Synthetic data Three component (Z, N-S, E-W) velocity wavefield Record length 10500s Sampling rate is 1s Format AH No instrutment response Add real noise from GEOSCOPE TAM

26 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Station PAYG for event 09 (coupling between T, L and Z) for Valerie 1D model spectrum synthetic T L Z

27 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Z component for station PAYG of event 09 Blue (3D model) and red (1D model) Filtered ( >200s)

28 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland L component for station PAYG of event 09 Blue (3D model) and red (1D model) Filtered (>200s)

29 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland T component for station PAYG of event 09 Blue (3D model) and red (1D model) Filtered >200s

30 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Seismic noise for GEOSCOPE station TAM E and N component of noise is much stronger than Z component

31 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland download http://www.ipgp.jussieu.fr/~qyl/benchmark_no_noise (about 1G) http://www.ipgp.jussieu.fr/~qyl/benchmark_with_noise (about 1G) README, 1D reference model, Source wavelet and dataset

32 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland Conclusions Perform benchmark of benchmark A complex 3D global anisotropic elastic model has been created A high quality anisotropic elastic dataset has been created Data and model (after blind test) are freely available

33 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland uses phase velocity inversion Waveform inversion CMT inversion Limitations Minimum period 32s

34 www.spice-rtn.org SPICE Research and Training Workshop III, July 22-28, Kinsale, Ireland acknowledgement SPICE Service de Calcul Parallèle, in Institut de Physique du Globe de Paris Sergei Lebedev (University of Utrecht)


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