- journal_title：Geophysics
- Contributor：Hui Liu ; Hua-wei Zhou ; Wenge Liu ; Peiming Li ; Zhihui Zou
- Publisher：Society of Exploration Geophysicists
- Date：2010-
- Format：text/html
- Language：en
- Identifier：10.1190/1.3502665
- journal_abbrev：Geophysics
- issn：0016-8033
- volume：75
- issue：6
- firstpage：U39
- section：SEISMIC VELOCITY/STATICS
First-arrival traveltime tomography is a popular approach to building the near-surface velocity models for oil and gas exploration, mining, geoengineering, and environmental studies. However, the presence of velocity-inversion interfaces (VIIs), across which the overlying velocity is higher than the underlying velocity, might corrupt the tomographic solutions. This is because most first-arrival raypaths will not traverse along any VII, such as the top of a low-velocity zone. We have examined the impact of VIIs on first-arrival tomographic velocity model building of the near surface using a synthetic near-surface velocity model. This examination confirms the severe impact of VIIs on first-arrival tomography. When the source-to-receiver offset is greater than the lateral extent of the VIIs, good near-surface velocity models can still be established using a multiscale deformable-layer tomography (DLT), which uses a layer-based model parameterization and a multiscale scheme as regularization. Compared with the results from a commercial grid-based tomography, the DLT delivers much better near-surface statics solutions and less error in the images of deep reflectors.