关键词: 层析成像, 初至波, 近地表速度结构, 活断层, 静校正

Abstract:

The complexity of the urban environment, the strong background interference and the serious reconstruction of the superficial layers made the exploration depth range of the seismic section limited and the subsurface structure information of shallow surface can not be obtained. In this paper, we used the tomographic imaging technique taking advantage of the first-arrival travel time in seismic records to invert the Luoyang shallow seismic data and obtained the near-surface velocity distribution and static correction of this section. As well as, we analyzed and discussed the results based on the existing borehole geological data. The researches show that the tomography technique not only made up for the lack of shallow reflection data to a certain extent, but also provided the reliable velocity information for post-migration and time-depth conversion. At the same time, the tomography also eliminated the influence of near-surface static correction and improved the imaging effect of seismic data, which had a good application value.

Key words: tomography, first break, near surface velocity model, active fault, static correction