Detecting near-surface objects with seismic traveltime tomography:Experimentation at a test site

• Main Author: Sawasdee Yordkayhun
• Format: Article
• Language: English
• Published: Prince of Songkla University 2011-08-01
• Series: Songklanakarin Journal of Science and Technology (SJST)
• Subjects: seismic tomography; traveltime; inverse theory; near-surface object
• Online Access: http://rdo.psu.ac.th/sjstweb/journal/33-4/0125-3395-33-4-477-485.pdf

In environmental and engineering studies, detecting shallow buried objects using seismic reflection techniques iscommonly difficult when the acquisition geometry and frequency contents are limited and the heterogeneity of the subsurfaceis high. This study demonstrates that such near-surface features can be characterized by taking advantage of P-wavetraveltimes of seismic data. Here, a seismic experiment was conducted across a buried drainpipe series, the main target, withthe goal of imaging its location. Tomography is implemented as an iterative technique for reconstructing the P-wave velocitymodel from the first-arrival traveltimes. To study the reliability of the method, a set of starting model was tested and asynthetic data was generated. After evaluation and selection of the best model, the resulting image was interpreted. The lowvelocity zone in the tomographic image coincides well with the location of a drainpipe series and surrounding altered grounddue to its installation. The existence of buried objects at the test site confirms and demonstrates the potential of the methodapplication.