ISTerre seminar

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The Seismic Response of Faults to Weak Perturbations: A New Probe Into Earthquake Physics and Fault State

Friday 6 November 2026 - 11h00

Eric Beaucé - ISTerre
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Faults respond to exceedingly weak stress perturbations as small as 1kPa, the equivalent of 1% of the atmospheric pressure. This response holds critical information on the physics of fault zone deformation and fault state. Expanding seismic networks and growing archives as well as machine-learning-based earthquake detection and location algorithms are redefining our ability to study the once-elusive seismic response of faults to kPa-perturbations such as tidal stresses and seasonal, hydrological loading. In this presentation, I will show how measuring and characterizing the modulation of seismicity by tidal stresses allows us to provide in-situ constraints of important frictional parameters, with direct implications for earthquake nucleation properties, and even to infer the loading rate on the seismogenic patches of the fault. Alternatively, these observations may be used to emphasize the limitations of laboratory-based frictional models. Moreover, I will demonstrate how this observational framework constitutes a promising tool to monitor faults throughout their seismic cycle, in particular to study possible preparatory mechanisms leading up to large earthquakes. This presentation will mainly focus on recent work on the Ridgecrest fault zone in California and its 2019 M7.1 earthquake. I will end by outlining future work on faults that produced much smaller (Parkfield, 2004 M6.0 earthquake) and much larger (Tohoku-Oki, 2011 M9.0 earthquake) events.

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Organizing team : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

Informations de visio :

https://rendez-vous.renater.fr/private/seminaire_equipe_cycle__8qzec4btbf8u_79120b-64adbb-750e0c