Abstract: Devices and methods for placing sensors underground are described. A preferred device has a first structure and a second structure that are placed into the ground. A third structure is connected to a portion of the first structure. The second structure is removed from the ground, leaving sensors or other equipment underground.

Abstract: A seismic wave generating device and methods for generating seismic waves having a relatively strong longitudinal energy and a relatively weak transverse energy are disclosed. A device may have a hollow casing and a striking member passing through the hollow casing, the striking member or the hollow casing bearing a spacing member. A method may drive the hollow casing into the earth, then remove earth from within the hollow casing. The method may place a striking member through the hollow casing and may drive the striking member further into the earth to create seismic waves with a relatively strong longitudinal energy and a relatively weak transverse energy.