Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Earthquakes as multiscale dynamic ruptures with heterogeneous fracture surface energy

Abstract : We propose a model of the wide-scale growth of dynamic rupture during an earthquake, based on our multiscale simulation of a planar crack in a three-dimensional homogeneous elastic space. A simple slip-weakening law governs the fracture/friction processes, and its characteristic parameters, slip-weakening distance and fracture surface energy, have multiscale heterogeneous distributions. We consider a set of randomly distributed circular patches, whose diameter is proportional to the fracture surface energy. Each patch represents an asperity between irregular fault surfaces, and the size-number relation of the patches obeys power law statistics. We assess rupture propagation from a small instability using a boundary integral equation method with a renormalization technique. Although most events stop shortly after their initiation, some grow, triggering neighboring patches of similar size. Small and large events show statistically self-similar properties of rupture growth and stop spontaneously without requiring a special stopping mechanism. The rupture velocity locally exceeds the shear wave speed but globally remains subshear speed due to the increase of the average fracture energy as the rupture grows. The relation between size and frequency of events is a power law, which is explained by the triggering probability between patches. As a consequence of statistically self-similar random triggering growth, we observe a distinct ''main phase'' in seismic waves similar to those of natural earthquakes, but we cannot estimate the final size of the event from the initial part of the seismic waves. If this is true for the real earthquakes, predicting the size of a future earthquake would be quite difficult.
Type de document :
Article dans une revue
Liste complète des métadonnées
Contributeur : Frédérique COUFFIGNAL Connectez-vous pour contacter le contributeur
Soumis le : jeudi 18 août 2022 - 16:52:45
Dernière modification le : jeudi 18 août 2022 - 16:59:03


Journal of Geophysical Researc...
Fichiers éditeurs autorisés sur une archive ouverte




Satoshi Ide, Hideo Aochi. Earthquakes as multiscale dynamic ruptures with heterogeneous fracture surface energy. Journal of Geophysical Research, American Geophysical Union, 2005, 110 (B11), ⟨10.1029/2004jb003591⟩. ⟨hal-03753772⟩



Consultations de la notice


Téléchargements de fichiers