FULL WAVEFORM INVERSION OF GAS HYDRATE-RELATED BOTTOM SIMULATING REFLECTORS
天然气水合物似海底反射层的全波形反演

A full waveform inversion strategy is proposed for gas hydrate-related bottom simulating reflector. This method is used for stratified elastic media and is implemented in intercept time-slowness domain. It consists of two steps with a combination of a global search method and a nonlinear local search method. In the first step, long wavelength parts of velocity structure are estimated by very fast simulating algorithm, when travelling time information is used. In the second step, short wavelength velocity variations are included into the model by conjugate gradient method, and waveform information in intercept time-slowness domain is used. Multi-grid parameter technique is used in our full waveform inversion. The method is applied to study a double BSR in the eastern Nankai accretionary wedge, and the results show that the full waveform inversion is an important tool for gas hydrate research.