Faculty candidate seminar - Alice-Agnes Gabriel

05/23/2019 - 12:45pm
Eckart 227
Event Description: 


Theoretical/Computational Geophysics

DATE:          May 23rd, Thursday, 12:45 p.m.  

LOCATION:     Eckart 227
SPEAKER:      Alice-Agnes Gabriel
            Ludwig Maximillians University
Physics-based modeling of puzzling earthquake dynamics: Subduction zones, complex crustal fault networks and induced seismicity
Earthquakes are highly non-linear multi scale phenomena encapsulating the geometry and rheology of shear fracture inside the Earth's interior emanating destructive seismic waves. Using physics-based earthquake scenarios, modern numerical methods and hardware specific optimisations have shed light on the dynamics, and severity, of puzzling earthquake behaviour. This is specifically useful in tectonic settings which are currently underrepresented in operational seismic or tsunami hazard assessment, as well as on the much smaller scales of geo-reservoirs. I will present recent examples of physics-driven interpretations that can be integrated synergistically with established data-driven efforts, including (i) the 2016 Mw 7.8 Kaikoura, New Zealand earthquake, considered the most complex rupture observed to date, (ii) the September 2018, Mw 7.5 Sulawesi earthquake occurring on the Palu-Koro strike-slip fault system followed by an unexpected localized tsunami and (iii) large-scale scenarios of the 2004, Mw 9.1-9.3 Sumatra-Andaman earthquake and tsunami.
The degree of realism and accuracy by these models has been enabled  by the open-source software SeisSol (www.seissol.org)  which couples seismic wave propagation of high-order accuracy in space and time (minimal dispersion errors) with frictional fault failure, off-fault inelasticity and visco-elastic attenuation. SeisSol exploits unstructured tetrahedral meshes to account for complex geometries, e.g. high resolution topography and bathymetry, 3D subsurface structure, and complex fault networks. I will lastly discuss exploiting expected exascale computing infrastructure with the ExaHyPE high-performance engine for hyperbolic systems of PDEs (www.exahype.eu). Specifically, we aim to represent complex geometries with novel geometric transformations and multi-physics by diffuse interfaces on adaptive cartesian meshes, thus avoiding manual meshing. 
Faculty Host:  Catherine de Groot-Hedlin (cadegroothedlin@ucsd.edu)
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