Priddis pump-probe experiment

Gary F. Margrave, David C. Henley, Han-xing Lu, Kevin W. Hall, Kayla Bonham, Malcolm B. Bertram, Eric V. Gallant, Joe Wong

A novel exploration technique has been proposed, whereby the earth is continuously excited by a strong seismic signal, and concurrently `probed' by a more transient seismic impulse. The idea is that the background field, by exciting the fluids within rock layers to vibrate with respect to the rock matrix, will significantly change the rock properties across layer boundaries, causing them to respond differently to seismic impulses than when the rocks are not perturbed by the background signal. We conducted a small-scale 3C-2D seismic survey at our Priddis test site to try to test this proposed technique, specifically targeting the water table as a prospective layer boundary. Two different `background' surveys were conducted, as well as three `pump-probe' experiments, all on the same profile. Our preliminary analysis of the data shows small differences between a `background' survey and each of the `pump-probe' surveys; but our analysis is not yet refined enough to determine the significance of these differences, if any.