Slip distributions on intersecting normal faults

Slip distributions on normal faults often are asymmetric and display multip le local maxima. Numerically computed slip distributions from elastic model s indicate that such irregular slip distributions can be caused by mechanic al interaction between intersecting faults that produce local perturbations of the stress field resolved on the faults. A three-dimensional boundary element model based on the displacement discon tinuity method has been used to analyze the mechanical interaction of fault s that form Y- or T-shaped intersections. Slip distributions are asymmetric with a steeper slip gradient toward the line of intersection. Multiple sli p maxims occur, depending on the angle between the faults, but generally th ey are not located along the intersections, nor at the fault centers. Examples of intersecting normal faults taken from oil reservoir seismic sur veys and sandbox experiments have been used to confirm the application of t he theoretical results. Despite considerable simplifications in terms of ge ometry and boundary conditions, the computed slip distributions capture the characteristics of the observed slip distributions. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.