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Tuesday, May 14, 2024
3:00 PM - 4:00 PM
Annenberg 213

Special Seminar in Applied Mathematics

A theoretical framework for fault-slip styles from aseismic creep to regular earthquakes
Davide Zaccagnino, PhD student in Geophysics, Department of Geophysics, Sapienza University,
Speaker's Bio:
I am a theoretical physicist and a passionate about physics of natural hazards, above all earthquakes. Since November 2021, I have been working at my PhD project “An integrated approach to mid-term seismic prediction” under the mentorship of Prof. Carlo Doglioni and Dr. Luciano Telesca. I am interested in understanding how seismicity organizes itself in space and time and, more in general, in its collective physical properties. I focus my research activity on physical modeling using the framework of disordered, critical and complex systems. My main goal is a deep knowledge of the physics of earthquakes, which ultimately means how large-scale crustal instability develops, in order to get reliable seismic hazard assessment. I also do research in the field of seismotectonic and geodynamics.

The mechanical deformation of rocks is ruled by a stick-slip behavior in the brittle crust, while plastic flows mostly accommodate strain within weaker layers. The style of slip is inherently related to both fault strength and topology and rock rheology, so that the nature of the coupling between fractured and ductile regions and its associated transition zone play a crucial role in the dissipation of stress accumulated over time in the adjoining volumes. The observational evidence suggests that the transition is spread over a relatively wide range of depths, and it is affected by several parameters such as the strain rate, rock rheology, temperature, and pore pressure even during the different stages of seismic activity. Consequently, understanding how stress could be released using a universal physical mechanism, being feasible a priori the whole range of fault slip styles - from aseismic creep to regular earthquakes - may allow a comprehensive explanation of several apparently disconnected phenomena. Among them, the difference between deep and crustal earthquakes, the temporal dependency of the seismogenic thickness during the various stages of seismic activity and the impact of focal depth on the statistical properties of seismicity. The seminar is devoted to discussing the topic in the framework of turbulent transitions. The approach is suitable for several applications ranging from geothermal environments to subduction zone modelling. Moreover, it might be useful to unveil severe hazard potential in regions featured by long earthquake recurrences.

For more information, please contact Jolene Brink by phone at 6263952813 or by email at [email protected].