Geophysical methods such as multichannel analysis of surface waves (MASW), and electrical resistivity tomography (ERT) are capable of imaging shallow subsurface in karst terrain by conducting a survey the ground without drilling. Utilizing two or more geophysical techniques is important to provide a reliable data interpretation. In this study, electrical resistivity tomography and multi-channel analysis of surface waves data were acquired at a study area in Phelps County in the south-central part of Missouri. The objectives of the investigation were (1) to image the subsurface in the study area to a depth of 70 feet, (2) to compare the ERT profiles generated using both the dipole-dipole and the Wenner-Schlumberger arrays, (3) to assess how variations in the MASW array configuration affected the MASW data quality, and (4) to compare the interpreted top-of-rock based on the ERT and the MASW data. The subsurface in the study area was imaged to a depth of 70 feet using the ERT method. Soils were categorized as either dry, moist or moist and clayey. Limestone bedrock was also imaged and categorized as weathered or intact. The top-of-rock, as per the ERT interpretations, was consistent with the MASW-estimated depths to top-of-rock and correlated well with the 70 ohm-m contour value.
Presentation Date: Wednesday, October 17, 2018
Start Time: 1:50:00 PM
Location: Poster Station 6
Presentation Type: Poster