Development of earthquake source physics models for the seismological assessment of future earthquakes and ground motion prediction in Alpine regions

Cyrill Baumann (ETHZ), and Luis Dalguer (ETHZ)

Earthquake numerical models based on physics of the causative rupture and wave propagation, incorporating conservation laws of continuum mechanics, frictional sliding, and the state of stress in the crust, have expanded our understanding of both source- and propagation-dominated ground motion phenomena (e.g. energy channeling, directivity effects, supershear). The assessement of those phenomena that have been identified in physics-based numerical simulations are required if we are to adequately evaluate the level and variability of near-source ground motion, for potential expected events in a specific zone, for seismic hazard and seismic risk mitigation.

In the present project we propose to develop suite of earthquake source physics-based numerical models to study rupture dynamic complexity and the resulted near-source ground motion, implementing laboratory-based constitutive friction models (rate- and state-dependent friction law) for different geological sttructures in the Alpine regions, for the seismological assessment of past and future earthquakes and ground motion prediction in the Alpine regions.

For this purpose, we work with one of the most accurate and efficient open-source code to develop research on the field of earthquake source dynamics. This is the Support Operator Rupture Dynamics code (SORD). The SORD code developed by Ely (Ely et al. 2008a, 2008b) was implemented using a generalized finite difference scheme that can utilize meshes of arbitrary structure and incorporate irregular geometry with the capability to model general fault geometry and topography. SORD solves the three dimensional visco-elasto-dynamic equations of motion.

This source modelling takes place in context of the project COGEAR (COupled seismogenic GEohazards in Alpine Regions), which is an interdisciplinary natural hazard project for investigating the hazard chain induced by earthquakes. It addresses tectonic processes and the related variability of seismicity in space and time, earthquake forecasting and short-term precursors, and strong ground motion as a result of source and complex path effects. For further information please visit COGEAR's website.