François X. Passelègue
EMRP Earth Magnetism & Rock Physics
The 2021 Division Outstanding Early Career Scientist Award is awarded to François X. Passelègue for his outstanding research in the field of experimental rock physics and novel understanding of earthquake dynamic rupture nucleation and propagation, and frictional and ductile processes.
François X. Passelègue is receiving the Earth Magnetism and Rock Physics Division’s Outstanding Early Career Scientist Award for his outstanding contribution in the fields of rock physics and rock mechanics, which opened up new knowledge on the physics of seismic rupture as well as frictional and ductile processes that will allow experimentalists to continue to add greatly within these fields.
The research of Passelègue aims mainly at better understanding the physics of seismic rupture nucleation-propagation and seismic slip by means of laboratory experiments performed with triaxial and rotary shear apparata integrated by novel acoustic-based methodology. His work on the transition from sub-Rayleigh to supershear ruptures in natural rocks was published in Science.
Passelègue also worked on the role of normal stress in controlling the transition from silent slip to foreshock activity preceding a main frictional instability, an interest on the precursory and earthquake nucleation phase he has maintained over the years. In a current study Passelègue used mixing scaling law arguments, laboratory experiments and field observations to demonstrate that the precursory moment release, whether seismic or aseismic, must scale with the co-seismic one, i.e., that large earthquakes must have a large and long earthquake nucleation phase. In addition to dynamic rupture nucleation and propagation, Passelègue also studied ductile processes as well as frictional process. He is also interested in field observations, as attested by the field-based studies he conducted. Passelègue has experience in a broad range of experimental systems and is knowledgeable and versatile in theoretical analysis of earthquake source mechanics and seismology.