HR: 1340h
AN: S23B-1377    [Abstracts]
TI: Frechet kernels for wave equation reflection tomography on curvilinear coordinates
AU: * Burdick, S
EM: sburdick@mit.edu
AF: Department of EAPS, Massachusetts Institute of Technology, 77 Massachusetts Ave. 54- 911, Cambridge, MA 02139, United States
AU: de Hoop, M V
EM: mvdehoop@math.purdue.edu
AF: Department of Mathematics, Purdue University, 150 N. University St., West Lafayette, IN 47906, United States
AU: van der Hilst, R D
EM: hilst@mit.edu
AF: Department of EAPS, Massachusetts Institute of Technology, 77 Massachusetts Ave. 54- 911, Cambridge, MA 02139, United States
AB: We develop a method of wave equation reflection tomography where the misfit criteria are not based on the correlation of waveforms from specific phase arrivals, but on the annihilation of the observed wavefield. Optimization thus uses the redundancy in the data to minimize the difference between images produced at different slownesses. This method, which is a generalization of differential semblance optimization, admits for the formation of caustics. It is established in exploration seismology, and we seek to modify it for application to large scale geological surveys including passive data, e.g. from USArray. In doing so, irregular source and receiver placement and source depth must be taken into account. For higher computational efficiency in dealing with the large volumes of data, migration is carried out by large angle one-way wave propagators which can be based either on finite differencing or generalized screens. One shortcoming of one-way propagators is the requirement that waves must not be allowed to travel horizontally. In order to accommodate situations where turning waves occur, e.g. teleseismic studies or reflection off of tectonic features like lateral faults, we transform to curvilinear coordinates where the wavefront travels nowhere horizontally in the pseudodepth coordinate. By use of the adjoint state method, we develop finite frequency Frechet kernels on curvilinear coordinates which can be used with a variety of optimizations schemes.
DE: 7270 Tomography (6982, 8180)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting