Seismic focusing by a single planar fracture
Abstract
[1] A single plane fracture with an axially symmetric stress distribution behaves as a seismic lens that focuses seismic energy to a beam "waist'' at a focal plane. Both phase and amplitude effects on a seismic wave propagating across the fracture contribute to the lensing behavior. Radial gradients in the fracture specific stiffness cause wave refraction through a radially varying group time delay, while the fracture transmission amplitude approximates a Fresnel zone plate. This work demonstrates that a two-dimensional planar fracture, contrasted with three-dimensional geologic structures such as basins and domes, can focus seismic waves. Focusing of seismic waves by fractures should be considered in the interpretation of seismic data from fractured strata with heterogeneous stress distributions.
Published in:
Geophysical Research Letters 30,5 (2003) -;
Link to original published article:
http://dx.doi.org/10.1029/2002GL016264.
Keywords
parallel fractures;; waves;; rock;; transmission;; surfaces;; closure;; contact
Date of Version
January 2003
Recommended Citation
Oliger, A.; Nolte, D. D.; and Pyrak-Nolte, L. J., "Seismic focusing by a single planar fracture" (2003). Department of Physics and Astronomy Faculty Publications. Paper 401.
https://docs.lib.purdue.edu/physics_articles/401