# Physics-based rupture modeling of earthquake ground motions

**Advisor:** František Gallovič (MFF UK)

**Funding:** Grant supplements

**Website:** http://geo.mff.cuni.cz/~gallovic/

**Contact:** Frantisek.Gallovic@mff.cuni.cz

Understanding the physics of earthquake rupture initiation, propagation, and arrest is driven by advances in laboratory experiments, observational capabilities, and modeling approaches. Dynamic source models couple laboratory-derived friction along faults with seismic wave propagation in the surrounding Earth. Despite significant progress, validation of empirical friction laws, including spatial heterogeneity of the controlling dynamic parameters, against seismic data represents a significant challenge in the present-day earthquake physics.

Classical so-called kinematic source inversions trace observed seismic motion from the near-fault stations back onto the fault plane, to calculate how the fault rupture has evolved. These conventional techniques are well known for providing strongly non-unique solutions. Dynamic source inversions, recently elaborated at our department, seek for heterogeneous distribution of the governing stress and frictional parameters. They have the potential to overcome the non-uniqueness of the kinematic inversions due to the incorporation of a physically consistent earthquake rupture model, eventually permitting new tectonic and mechanical interpretations.

We seek an enthusiastic PhD student to work with the advisor on numerical simulations of earthquakes using dynamic rupture models. A candidate preferring theoretical work could focus on improvements of our GPU enabled simulation codes or parametric studies related to the rupture and ground motion variability. Candidates favoring real data modeling and data expertise could infer driving parameters by our Bayesian dynamic source inversion for a suitable event (preferably strike-slip recorded by numerous near-fault stations). This could include an earthquake that would occur during the PhD studies, resulting in its tectonophysical interpretation. Examples of the above-mentioned studies can be found in the references listed below.

Selected Publications

Gallovič, F., J. Zahradník, V. Plicka, E. Sokos, Ch. Evangelidis, I. Fountoulakis & F. Turhan (2020). Complex rupture dynamics on an immature fault during the 2020 Mw 6.8 Elazığ earthquake, Turkey, Commun. Earth Environ., in press.

Premus, J., F. Gallovič, L. Hanyk & A.-A. Gabriel (2020). FD3D_TSN: Fast and simple code for dynamic rupture simulations with GPU acceleration, Seism. Res. Lett. 91, 2881-2889.

Gallovič, F. & Ľ. Valentová (2020). Earthquake stress drops from dynamic rupture simulations constrained by observed ground motions, Geophys. Res. Lett. 47, e2019GL085880.

Gallovič, F., Ľ. Valentová, J.-P. Ampuero, A.-A. Gabriel (2019). Bayesian Dynamic Finite-Fault Inversion: 2. Application to the 2016 Mw6.2 Amatrice, Italy, Earthquake, J. Geophys. Res. Solid Earth 124, 6970-6988.