Field measurements of the roughness of fault surfaces
Résumé
We recorded the height of a granitic fault surface as a function of position along one-dimensional profiles. We show that the profiles exhibit an "anisotropic" scaling invariance: self-affinity. The difference between the maximum and the minimum height, and the standard deviation of the height, over a length L are proportional to L½, where (• 0.84. Other properties such as the Return Probability distribution or the Power Spectrum of the profile comfort this result. This self-affne property is in good agreement with recent works on artificial fractured surfaces. Previous studies at field scale are consistent with this concept.