thumper truck
n.— «Dawson has deployed three trucks to test 30-square miles that cover neighborhoods and non-residential areas in and around Fort Worth. The trucks emit a vibration into the ground ranging from 10-120 hertz. Small white boxes placed at 180-foot intervals are recording stations that can pick up the seismic signal from up to two miles away.…What some companies call a thumper truck.» —“Energy companies using seismic activity to test Barnett Shale through mid-August” by Erin Rice Pegasus News (Dallas, Texas) Aug. 5, 2008. (source: Double-Tongued Dictionary)