The effect of thermal pressurization on dynamic fault branching

Abstract : We numerically investigate the effect of thermal pressurization (TP) on fault branch behaviour during dynamic rupture propagation, a situation likely to occur during large earthquakes at subduction interfaces. We consider a 2-D mode II (in-plane) rupture in an infinite medium that propagates spontaneously along a planar main fault and encounters an intersection with a pre-existing branching fault. The fault system is subjected to uniform external stresses. We adopt the values used by Kame et al. We use the 2-D boundary integral equation method and the slip-weakening friction law with a Coulomb failure criterion, allowing the effective normal stress to vary as pore pressure changes due to TP. We reveal that TP can alter rupture propagation paths when the dip angle of the main fault is small. The rupture propagation paths depend on the branching angle when TP is not in effect on either of the faults, as described by Kame et al. However, the dynamic rupture processes are controlled more by TP than by the branching angle. When TP is in effect on the main fault only, the rupture propagates along the main fault. It propagates along the branch when TP is in effect on both faults. Finally, we considered the case where there is a free surface above the branch fault system. In this case, the rupture can propagate along both faults because of interaction between the free surface and the branch fault, in addition to TP on the main fault.
Type de document :
Article dans une revue
Geophysical Journal International, Oxford University Press (OUP), 2014, 196 (issue 2), p. 1237-1246. 〈http://oxfordindex.oup.com/view/10.1093/gji/ggt457〉. 〈10.1093/gji/ggt457〉
Liste complète des métadonnées

https://hal-irsn.archives-ouvertes.fr/irsn-01314626
Contributeur : Sébastien Hok <>
Soumis le : mercredi 11 mai 2016 - 16:34:58
Dernière modification le : mardi 29 mai 2018 - 12:50:42

Lien texte intégral

Identifiants

Collections

Citation

Yumi Urata, Sébastien Hok, Eiichi Fukuyama, Raul Madariaga. The effect of thermal pressurization on dynamic fault branching. Geophysical Journal International, Oxford University Press (OUP), 2014, 196 (issue 2), p. 1237-1246. 〈http://oxfordindex.oup.com/view/10.1093/gji/ggt457〉. 〈10.1093/gji/ggt457〉. 〈irsn-01314626〉

Partager

Métriques

Consultations de la notice

104