Summary
High-performance computing empowered dynamic rupture modeling, assimilating available regional knowledge, such as fault geometry, community velocity and stress models, and topography, is approaching a state of maturity and computational efficiency, enabling physics-based interpretations of past earthquakes, that may complement data inversion efforts. Our recent modeling efforts to illuminate the elusive mechanics of the Ridgecrest, California, earthquake cascade, illustrate how dynamic rupture modeling may indeed shed light on the underlying physics of past earthquakes. Well-constrained studies integrating source observations and earthquake physics demonstrate that the same modeling approach can be used to produce realistic scenarios of future earthquakes, and therefore to inform earthquake and tsunami hazards. For example, our earthquake scenarios of the active Mai’iu fault in Papua New Guinea, a low-angle normal fault, that dips 16-24° at the surface, exploring distinct fault-local stress scenarios, allow identifying under which conditions such detachment faults can host moderate to large earthquakes. Our 3D dynamic rupture simulations of potential earthquakes along the Cascadia megathrust, informed by geodetic models, allowing us to assess margin-wide rupture behaviors, offer another illustration of the benefits of using physics-based earthquake scenarios to explore earthquake and tsunami hazards.
Brief biography
Thomas Ulrich is a researcher with 12 years of experience in seismology and numerical modeling. After graduating at Ecole Centrale Paris and spending 1 year at Escola Tècnica Superior d'Enginyeria Industrial de Barcelona, in Spain, Thomas worked as a Natural risks engineer at the Bureau de Recherches Géologiques et Minières (BRGM), in Orleans, France from September 2009 to December 2014. There, he conducted research in seismology and earthquake engineering with a strong focus on numerical modeling. He then started a PhD in geophysics at Ludwig Maximilian University of Munich (Germany), in the Department of Earth and Environmental Sciences, with Prof. Alice Gabriel. His work there aimed at a better understanding of the dynamics of previous large earthquakes using realistic 3D dynamic rupture scenarios. During his PhD, he developed models of two multi-faults crustal earthquakes, the 2016 Mw7.8 Kaikōura earthquake, one the of the most complex known earthquake involving at least 21 faults, and the 2018 Mw7.5 Palu earthquake, a very fast (supershear) earthquake that triggered an expected and deadly tsunami. Thomas successfully defended his PhD in 2020 with “summa cum laude”. Since 2020, Thomas is a postdoctoral researcher in the same group of Prof. Alice Gabriel. In his current project (founded by Geothermie-Allianz Bayern), he combines 3D dynamic rupture modeling with reservoir modeling to give insight into seismic hazard.