Curved slip zones in an elastic half-plane

Slip on a curved fault loaded by far-field compressive stress induces changes in normal stress along the fault surface. A two-dimensional crack model is developed to quantify these stresses for curved fault geometries. Under compressional tectonic loading, slip is retarded on the planar slip zones of higher dips, but enhanced if the dip decreases with depth. On the other hand, under extensional tectonic loading, slip is retarded on the planar slip zones of smaller dips, but enhanced if the dip increases with depth. Curvature of a concave-downward slip zone enhances compressive normal stress at the shallow end of the slip zone under compressional tectonic loading, tending to prevent propagation of the slip zones to the free surface. On the other hand, the curvature of a concave-upward slip zone reduces the compressive normal stress at the shallow end under the uniform extensional tectonic loading, thus assisting propagation of slip zones to the free surface. By contrast, for deep slip zones, the changes in normal stress are practically not affected by the fault curvature. The results show that the magnitude of induced normal stresses is sharply localized near the bend. -from Authors