Depth characterization of shallow aquifers with seismic reflection, Part II—Prestack depth migration and field examples

Depth Characterization of Shallow Aquifers with Seismic Reflection, Part II—Prestack Depth Migration and Field Examples

It is common in shallow seismic studies for the compressional-wave velocity in unconsolidated sediments to increase by a factor of four or more at the transition from dry or partial water saturation to full saturation. Under these conditions, conventional NMO velocity analysis fails and leads to large depth and layer thickness estimates if the Dix equation is assumed valid. Prestack depth migra...

Depth Characterization of Shallow Aquifers with Seismic Reflection, Part I—The Failure of NMO Velocity Analysis and Quantitative Error Prediction

As seismic reflection data become more prevalent as input for quantitative environmental and engineering studies, there is a growing need to assess and improve the accuracy of reflection processing methodologies. It is common for compressional-wave velocities to increase by a factor of four or more where shallow, unconsolidated sediments change from a dry or partially watersaturated regime to f...

seismic refraction and downhole survey for characterization of shallow depth materials of bam city, southeast of iran

seismic refraction and downhole survey were employed to study dynamic characteristics of subsurface materials in bam city, southeast of iran. the data acquisition was performed at 160 p and s-wave refraction stations and 15 boreholes in the city. to derive velocity depth sections along these profiles as well as to perform downhole diagrams, seisimager software was used. based on the obtained va...

Pitfalls in Shallow Seismic Reflection

Substantial progress has occurred during the past 15 years in development of shallow CDP seismic-reflection techniques, but there are occasional interpretation problems with the resulting data. We discuss examples of the pitfalls of the method, along with some procedures to help avoid them. Problems that often occur include spatial aliasing of ground roll, interpreting processed ground-coupled ...

Landfill Leachate Migration through Shallow Unconfined Aquifers