HR: 11:00h
AN: S32A-03    [Abstracts]
TI: Approximate hybrid reconstruction of a stochastic medium from its seismic response using scale length analysis and partial spatial phase information
AU: * Carpentier, S
EM: carpo@geo.uu.nl
AF: Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Roy-Chowdhury, K
EM: kabir@geo.uu.nl
AF: Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AB: Stochastic description of the Earth is an alternate starting point for analysing broadband multichannel seismic reflection data. This may be preferable if there are indications for stochastic fabric of (upper and) lower crust. Seismic imaging of such media with relatively new statistical processing methods, however, needs careful attention. Using autocorrelation techniques similar to those in earlier researches, we estimate stochastic spatial distributions (scale lengths) from the wavefield backscattered from a synthetic stochastic medium. In addition to this we attempt to retrieve spatial phase (positional) information for the low wavenumber part of the spectrum only from the data as well. These parameters (scale length and partial phase) enable an approximate reconstruction of the original stochastic medium. The estimated scale lengths are less than their true values, something which has also been observed by earlier researchers, and must thus be corrected. The phase information of the low wavenumber part of the synthetic seismic wavefield has a moderate to high correlation with the equivalent spatial phase in the original stochastic medium. The partial spatial phase information in the seismic data could thus be a useful parameter in reconstructing the medium. Used together with the corrected scale length, it enables a partial reconstruction of the medium which includes a part of the low wavenumber structure embedded within a stochastic framework. The positions of shorter scale structures are of course uncertain and cannot be resolved from the seismic data with these methods. We plan to test these ideas on the DOBRE 2000 reflection dataset, measured across the Dniepr-Donets-Pripyat Basin in Ukraine.
DE: 7205 Continental crust (1242)
DE: 7260 Theory and modeling
DE: 7294 Instruments and techniques
SC: Seismology [S]
MN: 2005 Joint Assembly