P-06436–ground-vibrations-due-4 Published November 15, 2017 at 517 × 431 in P-06436–ground-vibrations-due-4 Fig. 3.6 The Ava95 system with the transducer in front and the recorder in the background. Photo by Kenneth Viking (2010) Fig. 3.6 The Ava95 system with the transducer in front and the recorder in the background. Photo by Kenneth Viking (2010).