High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological anisotropy at all scales

Francois Renard (1, 2) , Christophe Voisin (1) , Davd Marsan (1) , Jean Schmittbuhl (3)

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
2 PGP - Physics of Geological Processes [Oslo]
3 IPGS - Institut de physique du globe de Strasbourg

The surface roughness of a recently exhumed strikeslip fault plane has been measured by three independent 3D portable laser scanners. Digital elevation models of several fault surface areas, from 1 m2 to 600 m2, have been measured at a resolution ranging from 5 mm to 80 mm. Out of plane height fluctuations are described by non-Gaussian distribution with exponential long range tails. Statistical scaling analyses show that the striated fault surface exhibits self-affine scaling invariance with a small but significant directional morphological anisotropy that can be described by two scaling roughness exponents, H1 = 0.7 in the direction of slip and H2 = 0.8 perpendicular to the direction of slip.

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]

Francois Renard, Christophe Voisin, Davd Marsan, Jean Schmittbuhl. High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological anisotropy at all scales. Geophysical Research Letters, 2006, 33, pp.L04305. ⟨10.1029/2005GL025038⟩. ⟨hal-00201780⟩