Inferring upper-mantle structure by full waveform tomography with the spectral element method

Inferring upper-mantle structure by full waveform tomography with the spectral element method

S U M M A R Y Mapping the elastic and anelastic structure of the Earth’s mantle is crucial for understanding the temperature, composition and dynamics of our planet. In the past quarter century, global tomography based on ray theory and first-order perturbation methods has imaged longwavelength elastic velocity heterogeneities of the Earth’s mantle. However, the approximate techniques upon whic...

26 Global Waveform Tomography with the Spectral Element Method: A Second-Generation Upper-Mantle Model

The SEMum model of Lekic and Romanowicz (2011) (SEMum v.1) was the first global VS model obtained using spectral-element forward modeling (SEM: Komatitsch and Vilotte, 1998), and exhibits impressive amplitudes of heterogeneity in the upper 200km of the mantle compared to previous global models. Among other measures to make SEM-based modeling tractable, SEMum v.1 was developed using an homogeniz...

Full seismic waveform tomography for upper-mantle structure in the Australasian region using adjoint methods

S U M M A R Y We present a full seismic waveform tomography for upper-mantle structure in the Australasian region. Our method is based on spectral-element simulations of seismic wave propagation in 3-D heterogeneous earth models. The accurate solution of the forward problem ensures that waveform misfits are solely due to as yet undiscovered Earth structure and imprecise source descriptions, thu...

Full waveform tomography for radially anisotropic structure: New insights into present and past states of the Australasian upper mantle

Reliability of mantle tomography models assessed by spectral element simulation

S U M M A R Y Global tomographic models collected in the Seismic wave Propagation and Imaging in Complex (SPICE media: a European network) model library (http://www.spicertn.org/research/planetaryscale/tomography/) share a similar pattern of long, spatial wavelength heterogeneity, but are not consistent at shorter spatial wavelengths. Here, we assess the performance of global tomographic models...