Faulting characteristics of supershear earthquakes

Michel Bouchon (1) , Hayrullah Karabulut (2) , Marie-Paule Bouin (3) , Jean Schmittbuhl (4, 5) , Martin Vallée (6) , Ralph Archuleta (7) , Shamita Das (8) , François Renard (1) , David Marsan (9, 10)

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
2 Observatory and Earthquake Research Institute
3 OVSG - Observatoire Volcanologique et Sismologique de Guadeloupe
4 UNISTRA - Université de Strasbourg
5 CNRS - Centre National de la Recherche Scientifique
6 GEOAZUR 6526 - Géoazur
7 Department of Earth Science
8 Department of Earth Sciences [Oxford]
9 USMB [Université de Savoie] [Université de Chambéry] - Université Savoie Mont Blanc
10 ISTerre - Institut des Sciences de la Terre

Recent observations of large continental strike-slip earthquakes show that different fault segments may rupture at different speeds and that rupture may propagate faster than the shear wave velocity of surrounding rocks. We report that all the documented occurrences of supershear rupture are associated with faults which have simple geometry. The surface trace of these faults is described in the field or seen on satellite images as remarkably linear, continuous and narrow. Segmentation features along these segments are small or absent and the deformation is highly localized. As theoretically predicted, supershear is clearly associated with Mode II rupture.

Mots clés: Earthquake rupture; Rupture velocity; Fault geometry; Earthquake dynamics; Supershear rupture

Domaines: Tectonique

Michel Bouchon, Hayrullah Karabulut, Marie-Paule Bouin, Jean Schmittbuhl, Martin Vallée, et al.. Faulting characteristics of supershear earthquakes. Tectonophysics, 2010, 493 (3-4), pp.244-253. ⟨10.1016/j.tecto.2010.06.011⟩. ⟨hal-00545483⟩