HR: 1340h
AN: T33A-1335    [Abstracts]
TI: Combining different data to constrain the anisotropic shear-wave velocity structure of the Earth's mantle.
AU: * Kustowski, B
EM: kustowsk@eps.harvard.edu
AF: Harvard University , 20 Oxford St., Cambridge, MA 02138 United States
AU: Ekstr\"{o}m, G
EM: ekstrom@eps.harvard.edu
AF: Harvard University , 20 Oxford St., Cambridge, MA 02138 United States
AU: Dziewo\'{n}ski, A M
EM: dziewons@eps.harvard.edu
AF: Harvard University , 20 Oxford St., Cambridge, MA 02138 United States
AB: Over the last 10 years, dozens of new stations of the Global Seismographic Network have been deployed in remote and previously uninstrumented regions. The seismograms recorded at these sites provide new constraints on the structure of the Earth's mantle. We investigate the effect of including new measurements of long-period body and mantle-wave waveforms in the tomographic inversion for the anisotropic shear-wave velocity structure of the mantle. To ensure good radial resolution throughout the mantle, we combine the waveform data with measurements of Rayleigh- and Love-wave phase velocities and a diverse data set of absolute and differential body-wave travel times. To further improve the ray-path coverage we test the consistency of the $SS-S$ and $ScS-S$ differential travel times ({\it Bolton}, 1996) with our travel-time data and include them in the inversion. All waveform, surface-wave and body-wave travel-time measurements are corrected according to the global crustal model {\it CRUST 2.0} ({\it Bassin et al.}, 2000). We parameterize the mantle model using 362 spherical splines and 14 radial B-splines and minimize both horizontal and vertical gradients to regularize the inverse problem. To alleviate the effect of an arbitrary choice between a continuous and split model across the 670-km discontinuity, we define a split parameterization and control the change across the discontinuity using norm damping. Finally, we focus our attention on the capability of the combined data set to resolve the anisotropic structure in the mantle parameterized in terms of the velocities of horizontally- and vertically-polarized shear waves.
DE: 7255 Surface waves and free oscillations
DE: 7200 SEISMOLOGY
DE: 7218 Lithosphere and upper mantle
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting