Elastic Impedance Revisited

P342 ELASTIC IMPEDANCE REVISITED Introduction 1 Elastic impedance is a relatively simple concept but is somewhat elusive in practice. Just as contrasts in an acoustic impedance profile convolved with a wavelet generate normal incidence seismic data there should be an "elastic impedance" profile whose contrasts would generate wide-angle reflections. The problem is that there is no simple closed form expression for this quantity. There are various ways to approximate it. One is to integrate Aki and Richards' (1980) approximation for the Zoeppritz equation (Connolly 1999 and Sena 1997). The result is useable but unsettling with angle-dependent (or even depth-dependent) fractional