Elastic Scattering By Planar Fractures

Blum, Thomas E. (Boise State University) | Snieder, Roel (Colorado School of Mines) | van Wijk, Kasper (Boise State University) | Willis, Mark E. (ConocoPhillips)


Remote sensing of fractures with elastic waves is important in fields ranging from seismology to non-destructive testing. While previous analytic descriptions of scattering mostly concern very large or very small fractures (compared to the dominant wavelength), we present an analytic solution for the scattering of elastic waves from a fracture of arbitrary size. Based on the linear-slip model for a fracture, we derive the scattered amplitude in the frequency domain under the Born approximation for all combinations of incident and scattered wave modes. Our analytic results match laser-based ultrasonic laboratory measurements of a single fracture in clear plastic, allowing us to quantify the compliance of a fracture.