Slip distributions on intersecting normal faults

Slip distributions on normal faults often are asymmetric and display multiple local maxima. Numerically computed slip distributions from elastic models indicate that such irregular slip distributions can be caused by mechanical 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 discontinuity method has been used to analyze the mechanical interaction of faults that form Y- or T-shaped intersections. Slip distributions are asymmetric with a steeper slip gradient toward the line of intersection. Multiple slip maxims occur, depending on the angle between the faults, but generally they are not located along the intersections, nor at the fault centers. Examples of intersecting normal faults taken from oil reservoir seismic surveys and sandbox experiments have been used to confirm the application of the theoretical results. Despite considerable simplifications in terms of geometry and boundary conditions, the computed slip distributions capture the characteristics of the observed slip distributions. (C) 1999 Elsevier Science Ltd. All rights reserved.