Keynote Speech – Session 2A

Time: Monday 31st August, 13:45 – 15:00 CEST; Location: LMU main building, room E004; Chair: Hans Bungartz

Hans-Peter Bunge Geophysics Section, Dept of Earth Sciences,
Ludwig-Maximilians Universität (LMU), Munich

“Data assimilation in global mantle flow models: theory, computational challenges and uncertainties in reconstructing global deep Earth structure back in time”

Talk abstract

The ability to extract the history of motion associated with large-scale structure that is imaged seismically in the Earth’s interior, such as thermal plumes or cold, subducting oceanic slabs, is crucial to constrain the deformation processes of mantle convection. Here we show, how fluid dynamic inverse theory, based on a variational approach, can be applied in a global circulation model of the mantle to project gross Earth structure back in time. We present the basic theory of the forward and
inverse problem, review geologic constraints, provide computational considerations relevant to the global flow problem with 100 million finite elements, and discuss uncertainties. The latter restrict the problem in practice, as our knowledge of deep Earth structure and its interpretation in terms of dynamic flow is necessarily limited.

Speaker bio
H.-P. Bunge is Chair of Geophysics at Munich University since 2003, and member of the Center of Advanced Studies at Munich University. Prior to his Munich appointment, he served on the Princeton faculty following an EU postdoctoral year at the Institut de Physique du Globe in Paris. He completed his Berkeley PhD in 1996, the majority of which he spent at Los Alamos National Laboratory, supported by the Institute of Geophysics and Planetary Physics (IGPP) and the Advanced Computing Laboratory (ACL).

His research interests lie in HPC modeling of problems in core, mantle and lithosphere dynamics. He developed fluid dynamic inverse theory to reconstruct gross Earth structure back in time. Bunge is Geophysics lecturer for ESA, member of the Munich LRZ Advisory Board, and member of the steering committee of the DFG Priority Program on Exa-Scale computing. He currently coordinates a data-driven DFG Priority Program on the opening history of the South Atlantic. A member of Academia Europaea and Bavarian Academy of Sciences, he served as President of EGUs Geodynamics Division from 2007-2009.