Topics of Section 2.5

The section 2.5 (Geodynamic Modeling) provides expertise in cutting-edge thermo-mechanical modeling of solid Earth dynamic processes at a large range of spatial (from regional to global) and temporal (from geological to human) scales. Particular focus is at the following themes:  

• Coupled thermo-mechanical and petrophysical modeling of lithosphere-scale deformation processes at plate boundaries.
• Modeling of mutual interaction of processes operating at different spatial and temporal scales (cross-scale modeling), and particularly
  (i) interaction between global- and regional-scale deformation processes and
  (ii) geological timescale deformation and seismic-cycle deformation processes.
• Modeling activity aimed at understanding and assessment of natural hazards like earthquakes and tsunamis.
• Modeling support for multidisciplinary projects carried out by the GFZ.
• Modeling the interaction of global plate motions, large-scale mantle flow and mantle plumes

GPS-Shield: Towards Robust Characterization of Tsunami Source in Few Minutes after an Earthquake
The catastrophic consequences of 2004 Indian-Ocean and 2006 Java tsunamis demand for developing modern and robust tsunami early warning systems. The greatest challenge of the GITEWS (German Indonesian Tsunami Early Warning System), led by the GFZ, is to provide early tsunami warning for the Indian-Ocean coast of Indonesia located close to the potential tsunami source and where tsunamis are expected to arrive only 20-40 minutes after an earthquake.

Modeling the Interaction of Global Plate Motions, Large-Scale Mantle Flow and Mantle Plumes
Processes near the Earth's surface are linked to the deep mantle and core. From plate reconstructions and geodynamic models, the distribution of slabs throughout the mantle is computed and compared to tomographic images. When slabs approach the lowermost mantle, the thermal boundary layer is displaced. Resulting heat flow variations at the core-mantle boundary are computed, and their effect on the core is considered. Computation also show how a thermo-chemical layer is shaped into large piles, mantle plumes are generated, and chemically distinct material from the base of the mantle is entrained in plumes. Implications on the stability of thermo-chemical piles in space and time are considered. Computations of mantle flow due to large-scale density heterogeneities, such as plumes and slabs, and imaged through mantle tomography also yield predictions, which can be compared to observed quantities. The current focus is on computing surface uplift and subsidence through so-called dynamic topography.

New look at mantle plumes
Mantle plumes are considered to be important components of the global mantle convection. Traditionally they are thought to represent hot and therefore buoyant volumes of mantle material having similar bulk chemical composition as the rest of the mantle.

Modelling Deformation at Plate Boundaries
There is growing understanding that processes at plate boundaries control the long-term deformation of the lithosphere and influence plate motion, and therefore may also significantly affect global convection. The type examples of deformation at convergent (Andean type) and continental transform plate boundaries (Dead Sea Transform and San Andreas Fault system) were analysed within several interdisciplinary projects (SFB 267, DESERT/DESIRE, ICDP-SAFOD) using advanced thermomechanical modelling techniques dealing with highly nonlinear rheology and involving high-performance parallel computing. The modelling was constrained by the comprehensive interdisciplinary field observations collected in those projects.