A Comparison of Vertical and Horizontal GPR Velocity Estimates in Alluvial Sediments
Abstract
We have measured the horizontal and vertical electromagnetic velocity through an alluvial, sand- and-cobble aquifer near Boise, Idaho. To measure the horizontal velocity, we deployed antennas in two wells 6.9 m apart. To measure the vertical velocity, we placed one antenna on the surface adjacent to a well and lowered the other antenna down that well. We collected data at three wells; two wells at either end and a well located in between the two end wells. We thus have one measure of the horizontal velocity and three measures of the vertical velocity. The horizontal and vertical velocity are essentially the same below the water table at 2 m depth. In the vadose zone, the velocities differ, but we think that refracted waves cause the velocity differences. The directional independence of the velocities indicates that we can assume isotropic models in our interpretation of the aquifer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2001
- Accession Number
- ADA396015
Entities
People
- Michael D. Knoll
- William P. Clement
Organizations
- Boise State University