First Arrive Wave Traveltime Tomographic Inversion of Marine Seismic Data

The first-arrival wave traveltime tomographic inversion is a key technology to solve the complex static correction problem of land data as an important means to establish the near-surface velocity model. However, the attention and application of refractive wave information of marine seismic data which possesses widely developed refractive wave have not been paid much attention. In this paper, the seismic tomographic inversion technique is applied to marine seismic data to obtain the velocity structure of the seabed. The main difference with the tomographic inversion of land data is:(1). The pick-up of the first-arrival time should be carried out after the minimum phase processing of the source signal to avoid the error due to the inaccurate first-arrival time picking of the mixed phase wavelet. (2). The depth and the velocity information of the seawater layer are used as the inversion constraint conditions to reduce the iterative error. The results of the actual 2D multi-channel survey line tomography show that the first-arrival wave traveltime tomography can invert the more accurate marine stratigraphic velocity structure.