Mid-Term Review Meeting, February 13-14, Tutzing Task group: Planetary scale Members from: LMU Munich IPG Paris INGV Bologna University of Oxford University of Utrecht ETH Zurich University of Oslo Courtesy of J. Woodhouse

Mid-Term Review Meeting, February 13-14, Tutzing Key scientific questions The knowledge of the 3D distribution of temperature and composition is essential to understand the dynamics of our planet. Mantle km depth How reliable are our imaging tools ? How good are our models ? How important is density, anisotropy and anelasticity for imaging ? Trampert et al., 2004

Mid-Term Review Meeting, February 13-14, Tutzing Towards some answers Benchmark (reliability of imaging tools) Database of existing models (quality of models) Assessment of models using SEM, local modes, full ray theory (quality of models) Tomographic techniques including data corrections, new inverse techniques and validity of classical forward theories (density, anisotropy, anelasticity) European reference model (joint with new FP6 NERIES) and a new global mantle model. During several task group meetings, we identified the following research themes:

Mid-Term Review Meeting, February 13-14, Tutzing The new road The questions and answers are not entirely new, but exiting possibilities for more insight are created by our ability to solve the wave equation numerically in fully 3D structures on modest Beowulf clusters. Courtesy of H. Igel

Mid-Term Review Meeting, February 13-14, Tutzing The benchmark (UiO, IPGP) A simple model (dlnVs) has been made to check the feasibility. Seismograms for the final model (dlnq, dlnVp, dlnVs, dlnr, anisotropy, approximate locations) are being calculated. Courtesy of S. Lebedev

Mid-Term Review Meeting, February 13-14, Tutzing Database of existing models (ETH) Most published models can easily be retrieved, plotted and compared. All model coefficients are distributed in a fixed format (Becker and Boschi, 2001) and where possible in the original format. All necessary reading software is also available. Becker and Boschi, 2001

Mid-Term Review Meeting, February 13-14, Tutzing Assessment of existing models In progress: So far, we contributed to the software database with the following codes: Calculation of seismograms using normal modes (IPGP) Modelling of propagation of surface waves in 3D structures by the mode coupling method (UiO) Calculation of phase velocity dispersion curves (IPGP) Ray tracing for body and surface waves in anisotropic media (ETH, UOx) Spherical harmonic package (ETH-USC)

Mid-Term Review Meeting, February 13-14, Tutzing Tomographic techniques Exact ray theory predicts multipathing to be more important than previously thought. (Ferreira and Woodhouse, 2005) Crustal corrections using SEM (UU), local modes (UiO), exact ray theory (UOx) Imaging using the neighbourhood algorithm and neural networks (UU) Covariance and resolution matrices for finely parameterized models (ETH)

Mid-Term Review Meeting, February 13-14, Tutzing European reference model In search of a consensus of what a European reference model should be, we (INGV and UU) organized a special session at EGU05 and EGU06 focused on different aspects of reference models.

Mid-Term Review Meeting, February 13-14, Tutzing PhDs and postdocs IPG Paris: 1) Yilong Qin, A SPICE synthetic dataset to benchmark global tomographic methods (UiO) INGV Bologna: 2) Daniel Stich, Spectral element moment tensor inversion from regional seismograms 3) Reneta Raykova, Local surface wave tomography from a broadband dense array in Northern Apennines University of Oxford: 4) Eoin McManus, Comparisons of ray theory with measurements made on spectral-element synthetic seismograms (UU) University of Utrecht: 5) Ebru Bozdag Testing and improving tomographic models using 3D numerical wave propagation (UOx) 6) Anne Sieminski, 3D anisotropy sensitivity kernels using adjoint methods ETH Zurich 7) Daniel Peter, Global surface wave tomography: membrane waves and adjoint methods (UOx) University of Oslo: 8) Digdem Acarel, Surface Wave Synthetic Data in Heterogeneous Regions (UU) 9) Laurent Guillot, Coupled local and radiation modes in regional seismic wave propagation