EGU24-20926, updated on 11 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Similarities and differences between natural and simulated slow earthquakes

Adriano Gualandi1,2, Luca Dal Zilio3, Davide Faranda4,5,6, and Gianmarco Mengaldo7,8
Adriano Gualandi et al.
  • 1University of Cambridge, Cambridge, United Kingdom of Great Britain (
  • 2Istituto Nazionale di Geofisica e Vulcanologia, Italy
  • 3Swiss Federal Institute of Technology (ETH), Switzerland
  • 4Laboratoire des Sciences du Climat et de l'Environnement, University of Paris-Saclay, Paris, France
  • 5London Mathematical Laboratory, London, UK
  • 6Laboratoire de Meteorologie Dynamique, Ecole Normale Superieure, Paris, France
  • 7National University of Singapore, Department of Mechanical Engineering, Singapore
  • 8Department of Aeronautics, Imperial College, London, UK

Earthquakes are understood as frictional instabilities taking place in weak zones of the Earth crust called faults. On the one hand, the lengthy recurrence time of earthquakes makes numerical simulations an invaluable tool to study consecutive ruptures of a given fault. On the other hand, it makes a direct comparison with nature difficult, if not currently impossible. Slow earthquakes, exhibiting lower recurrence times, serve as a viable alternative for validating models against real-world observations. We investigate similarities and differences between natural and simulated slow earthquakes using nonlinear dynamical system tools. We focus on slow earthquakes derived from Global Navigation Satellite System (GNSS) position time series in Cascadia and numerical simulations intended to reproduce their pulse-like nature and scaling laws. We provide metrics to evaluate the accuracy of simulations in mimicking slow earthquake dynamics, and we investigate the influence of spatio-temporal coarsening as well as observational noise. Findings indicate that numerical simulations exhibit average properties akin to natural occurrences. In addition, despite the usage of many degrees of freedom in numerical simulations, we retrieve a low average dimension, like the one obtained for Cascadia slow earthquakes, suggesting that a reduced order model may be a viable representation of slow slip events. Time-dependent, instantaneous properties show strong dependence on the variable considered for the analysis for numerical simulations, but not for natural observations. Our exploration show a possible way to extract dynamic attributes from kinematic information, and enriches the picture that we have of natural-scale friction We propose to use the suggested metrics as an additional tool to narrow the divergence between slow earthquake observations and dynamical simulations.

How to cite: Gualandi, A., Dal Zilio, L., Faranda, D., and Mengaldo, G.: Similarities and differences between natural and simulated slow earthquakes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20926,, 2024.