Detection of a Solution Cavity Adjacent to a Highway in Southwest Jordan Using Electrical Resistivity Methods

Abstract

A DC resistivity profiling experiment was conducted over a buried cavity using a SYSCAL-R2 resistivity instrument at the location of a proposed highway at the Ras en Naqab escarpment, Aqaba Province, southwest Jordan. The objective of the study was to evaluate the resolution of the resistivity technique in detecting and locating significant anomalies (high resistivity) over underground cavities. Resistivity profiling measurements were carried out utilizing the following arrays: (1) Alpha-Wenner; (2) Beta-Wenner; (3) Gamma-Wenner; (4) Pole-Pole; (5) Combined Head-on. Results of the survey demonstrated a strong correlation between resistivity anomalies and a subsurface void. An open and air-filled cavity exhibits markedly high-resistivity anomalies. In addition, the survey indicated that caverns with diameters as small as [Formula: see text] can be detected at shallow depths below surface and can be positioned using the resistivity profiling method. Correlations between field results obtained from different resistivity profiling arrays show that the head-on resistivity technique was found to be the most reliable since it showed details over the buried cavity. Results using other arrays were inconclusive.