Third Party Funds Group - Sub project
Start date : 01.11.2012
End date : 31.12.2015
Much of what one refers to as geological activity of the Earth is due to the fact that heat is transported from the interior of our planet to the surface in a planetwide solid-state convection in the Earth’s mantle. For this reason, the study of the dynamics of the mantle is critical to our understanding of how the entire planet works. Processes from earthquakes, plate tectonics, crustal evolution to the geodynamo are governed by convection in the mantle. Without a detailed knowledge of Earth‘s internal dynamic processes, we cannot hope to deduce the many interactions between shallow and deep Earth processes that dominate the Earth system. The vast forces associated with mantle convection cells drive horizontal movement of Earth’s surface in the form of plate tectonics, which is well known albeit poorly understood. They also induce substantial vertical motion in the form of dynamically maintained topography that manifests itself prominently in the geologic record through sea level variations and their profound impact on the ocean and climate system. Linking mantle processes to their surface manifestations is seen widely today as one of the most fundamental problems in the Earth sciences, while being at the same time a matter of direct practical relevance through the evolution of sedimentary basins and their paramount economical importance.Simulating Earth mantle dynamics requires a resolution in space and time that makes it one of the grand challenge applications in the computational sciences. With exascale systems of the future it will be possible to advance beyond the deterministic forward problem to a stochastic uncertainty analysis for the inverse problem. In fact, fluid dynamic inverse theory is now at hand that will allow us to track mantle motion back into the past exploiting the rich constraints available from the geologic record, subject to the availability of powerful geodynamical simulation software that could take advantage of these future supercomputers.The new community code TERRA-NEO will be based on a carefully designed multi-scale spacetime discretization using hybridized Discontinuous Galerkin elements on an icosahedral mesh with block-wise refinement. This advanced finite element technique promises better stability and higher accuracy for the non-linear transport processes in the Earth mantle while requiring less communication in a massively parallel setting. The resulting algebraic systems with finally more than 1012 unknowns per time step will be solved by a new class of communication-avoiding, asynchronous multigrid preconditioners that will achieve maximal scalability and resource-optimized computational performance. A non-deterministic control flow and a lazy evaluation strategy will alleviate the traditional over-synchronization of hierarchical iterative methods and will support advanced resiliency techniques on the algorithmic level.The software framework of TERRA-NEO will be developed specifically for the upcoming heterogeneous exascale computers by using an advanced architecture-aware design process. Special white-box performance models will guide the software development leading to a holistic co-design of the data structures and the algorithms on all levels. With this systematic performance engineering methodology we will also optimize a balanced compromise between minimal energy consumption and shortest run time.This consortium is fully committed to the interdisciplinary collaboration that is necessary for creating TERRA-NEO as new exascale simulation framework. To this end, TERRA-NEO brings top experts together that cover all aspects of CS&E, from modeling via the discretization to solvers and software engineering for exascale architectures.