3‐D subsurface displacement and strain fields for faults and fault arrays in a layered elastic half‐space

Abstract

A quantitative model using elastic dislocation theory has been developed to model the near‐field subsurface displacement field associated with faults and fault arrays within an elastic layer above an elastic half‐space. A fault is modelled as a surface across which there is a discontinuity in prescribed displacements. Fault displacements may be oblique as well as dip‐slip. The mathematical expressions for the surface and subsurface displacements are formed using the Thomson‐Haskell matrix technique. Faults may intersect the free surface or may be blind. The model has been used to determine the 3‐D surface and subsurface displacement fields for a rectangular fault with constant slip and for an elliptical fault on which the slip varies from a point of maximum displacement at the centre to zero displacement at an elliptical tip‐line. The 3‐D displacement field and associated strain tensor may be determined for individual slip events on a fault or for cumulative fault displacements. Displacement contour maps may be constructed for either originally horizontal, vertical or inclined horizons. The model has also been applied to multiple fault arrays. Copyright © 1992, Wiley Blackwell. All rights reserved