Boris Kaus (University of Mainz)

Boris Kaus (University of Mainz)
Wednesday, March 21, 2018 - 4:00pm to 5:00pm

Coupling geodynamic models with geological and geophysical data to constrain the rheology of the crust & lithosphere

The rheology of the lithosphere is one of the largest unknowns hampering our understanding of the dynamics of geological processes. As laboratory experiments have quite large uncertainties, particularly when extrapolated to geological conditions it is important to have an independent method to constrain the rheology of the lithosphere.

Here, I will discuss two ways in which this can be achieved by combining geodynamic models with either geological or geophysical data. The first example uses the regular spacing of crustal-scale folds in the geologically well-understood Zagros mountains to constrain the rheology of the crust in the area. The second example compares predictions from geodynamic forward models with geophysical data. By framing this in a Bayesian inverse modelling framework, we can derive optimal rheological parameters for the lithosphere with uncertainty bounds. An application to the India-Asia collision zone unambiguous shows that a low viscosity mantle lithosphere, as proposed by some, is inconsistent with GPS, gravity and topography data. Yet, we also find that there is not a single 'best-fit' model that fits the data. Instead, there are about 3 types of models that fit the data nearly equally well, which gives important clues which other data should be incorporated as well. Ongoing work on combining (adjoint) inversion approaches with 3D geodynamic models of the India-Asia collision zone and the Yellowstone magmatic system will be briefly discussed as well.

About the Speaker

As a geodynamicist my main interest is understanding how geological processes work, from the grain scale to the scale of a planet. We predominantly do this with the help of mathematical and numerical models, for which we develop new approaches in our group. Ongoing research projects include lithospheric-scale shear localization, the coupling between melt migration and lithosphere deformation, the formation of fold-and-thrust belts, the coupling between erosion, lithosphere dynamics and mantle flow, the dynamics of subduction zones as well as the development of new software that runs on high-performance computing systems.

My research is funded by the German Research Foundation, the European Research Council, and an ERC Starting Grant (2010-2015) and an ERC Proof-of-Concept Grant (2016-2017).

My teaching interest include Geophysics, Modelling of tectonic processes, The dynamics of the Earth and Lithosphere as well as anything related to Quantitative Geosciences.

About this Series

Weekly talks given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Lectures take place on Wednesdays from 3:45pm in MIT Building 54 room 915, unless otherwise noted.