
© Ebru Bozdağ
Ebru Bozdağ is an associate Professor at the Colorado School of Mines, joingly appointed by Geophysics and applied Math and Statistics.
ECS Co-Host this time is Ingo Stotz.
The DeepDyn seminar takes place online as a zoom-meeting. DeepDyn members will automatically receive the access link before the seminar. We ask external seminar guests to register for the seminar in order to receive the access link.
Earth’s deep interior and dynamics from adjoint tomography: mantle structure and anisotropy
Abstract
Adjoint tomography has become a routine tool in passive-source seismology with the advances in high-performance computing for the accurate simulations of wave propagation in complex media and incorporate them in seismic tomography to achieve high-resolution models of Earth’s interior. First-generation GLAD (GLobal ADjoint) models (GLAD-M15 (Bozdag et al. 2016), GLAD-M25 (Lei et al. 2020), GLAD-M35 (Cui et al. 2024)) were constructed globally by inverting crust and mantle simultaneously avoiding crustal corrections. Since Earth’s upper mantle and lithosphere show significant evidence for anisotropy related to deformation and composition, GLAD models were parameterized radially anisotropic in the upper mantle. Starting from GLAD-M25, we performed 28 conjugate gradient iterations and constructed model GLAD-M28-AZI by also including azimuthal anisotropy in the parameterization of the inverse problem where we inverted azimuthal and radial anisotropy simultaneously. Despite using minor- and major-arc surface waves from 300 earthquakes only, GLAD-M28-AZI approaches continental-scale resolution in regions with good data coverage (i.e., North America, Europe, etc.) depicting smaller-scale tectonic and flow patterns, giving us a chance to have a more detailed and unified view of the anisotropy globally. In the next step, we explore how anisotropy derived from seismic tomography compares to geodynamical modeling observations to have better insight into mantle dynamics. We will discuss our current results, challenges, and future directions in global seismology and tomography.