HR: 1340h
AN: S33A-1087    [Abstracts]
TI: A Raindrop Model for Passive Imaging
AU: * Snieder, R
EM: rsnieder@mines.edu
AF: Center for Wave Pgenomena Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401-1887 United States
AB: In passive imaging one reconstructs the Green's function that accounts for the wave propagation between two receivers by correlating the waveforms recorded at these receivers. This technique is important because it makes it possible to carry out seismic imaging without using coherent sources. With the deployment of US-Array as part of Earthscope, this opens up the possibility for dense intra-continental imaging without relying on intra-plate earthquakes. Passive imaging has been explained using normal mode theory, or by assuming 1D Earth models. I present an alternative derivation of passive imaging that is based on the simple analogue of raindrops that hit the water surface of a pond. A stationary phase analysis of the random scattering integral shows in a simple way that the correlation of the waveforms recorded at two receivers indeed leads to the correct Green's function. The model gives physical insight into the working of passive imaging. This insight helps to asses the use and limitations of passive imaging. \noindent Snieder, R., Extracting the Green's function from the correlation of coda waves: A derivation based on stationary phase, Phys. Rev. E, 69, 046610, 2004
DE: 7260 Theory and modeling
SC: Seismology [S]
MN: 2004 AGU Fall Meeting