Global high-resolution earth models

First immersion in the inaccessible jacket thanks to VR

A good understanding of convection in the Earth's mantle is of fundamental importance, as it is the fundamental cause of all plate tectonic movements of the Earth's surface. The slow creep-based material flow, which takes place in the approximately 3000 km thick layer of solid rock beneath the tectonic plates on time scales of hundreds of millions of years, regulates the transport of heat from the earth's interior to the surface. The amount of heat extracted from the earth's core below has a strong influence on the character and strength of the earth's magnetic field. In addition, the buoyancy forces responsible for mantle convection drive the tectonic plates and thus constantly change the earth's surface. The relative movement of the plates to each other leads to the permanent build-up of stresses at their boundaries, which are discharged by continuously recurring earthquake activity. Precise knowledge of the forces in the earth's mantle is therefore a basic prerequisite for modelling these natural disasters. Unfortunately, however, models of mantle dynamics are often only qualitative in nature. One of the fundamental problems is that the deep interior of our planet is not accessible for direct in situ measurements of the relevant parameters.

Fortunately, modern software and powerful supercomputers enable the numerical simulation of complex three-dimensional models of the temporal evolution of mantle convection. Today, the mainframe computers of the LRZ allow models with several hundred million grid cells, which provide us with quantitative estimates of the otherwise indeterminable parameters, such as buoyancy forces and temperature, as well as with predictions of the resulting Earth gravity field or seismic wave field, which can be compared with Earth observation. By 3-D visualization of the calculated physical parameters, which are created by the V2C group of the LRZ, we can examine our models in a way never imagined before, as if we were immersing ourselves into the earth's interior. Thus, the convective processes taking place thousands of kilometers below our feet are made accessible for the first time by a combination of simulation and high-end VR techniques. Future supercomputers will make it possible to compute the next generation of mantle convection models with even higher resolution, and thus even more Earth-like, so that we can come a step closer to our goal of quantifying the enormous forces at the bottom of the tectonic plates.

Prof. Dr. Hans-Peter Bunge, Dr. Bernhard S.A. Schuberth
Department of Earth- and Environmental Sciences
LMU München

Elisabeth Mayer, Lea Weil
Markus Wiedemann, Michael Käsdorf