58 GS11 Abstracts IP1 tional perspective. Multiscale Model Reduction Techniques for Flows in High-contrast Heterogeneous Media and Appli- J¨orn Behrens cations KlimaCampus University Hamburg The development of numerical algorithms for simulations
[email protected] of flow processes in large-scale highly heterogeneous porous formations is challenging because properties of natural ge- ologic porous formations (e.g., permeability) display high IP3 variability and complex spatial correlation structures which Recent Advances in Full Waveform Global Seismic can span a hierarchy of length scales. It is usually necessary Tomography of the Earth’s Mantle to resolve a wide range of length and time scales, which can be prohibitively expensive, in order to obtain accurate pre- Over the last 20 years, several generations of global tomo- dictions of the flow, mechanical deformation, and transport graphic models of the earth’s mantle elastic structure have processes under investigation. In practice, some types of been developed, relying on simple theoretical approxima- coarsening (or upscaling) of the detailed model are usually tions to the 3D wavefield (i.e. ray theory and first order performed before the model can be used to simulate com- normal mode perturbation theory). Now, it is possible to plex processes. Many approaches have been developed and compute accurate synthetics in spherical geometry for ar- applied successfully when a scale separation adequately de- bitrary 3D structures using numerical approaches, such as scribes the spatial variability of the subsurface properties the Spectral Element Method, which is particularly well (e.g., permeability) that have bounded variations. The suited for global waveform tomography. The challenge has quality of these approaches deteriorates for complex het- been shifted from theoretical limitations to the length of erogeneities without scale separation and high contrast.