This group of the USGS has an ATV that they use when the going gets tough. This is the same one they had during the Superstition Hills experiment in southern California in November 2000.
Over most of the trail the geophone connected to the Texan was stuck into the ground, and the Texan just left lying on the ground to fend for itself. In some places a few leaves were thrown on top to try and hide them. Each Texan costs about $2500, but they don't have much use beyond recording seismic activity. About the only thing of use to the normal person would be the two D-cell batteries inside each one. A couple of the Texans were moved around by some kind souls during the time that the instruments were deployed for this experiment, and two were stolen...which wasn't too bad. Hey, if you're you're reading this, and you are the one that took our Texans, give 'em back!
Some laws just have to be ignored in the name of science. (I think they had permission.)
Deployment doesn't consist of just dropping the Texans off the back of an ATV. Earlier in the year the entire route was surveyed with some sort of marker (usually a wooden stake) being placed every 50 meters (~160 feet). Each of these locations were assigned an ID number. When a Texan was placed at a location the location ID, the serial number of the Texan, the type of geophone (4.5Hz or 40Hz -- the frequency of the shock waves that the sensors are sensitive to), and in some cases a small description of the area, was recorded. The exact position of each Texan (using GPS) must be known to make sense out of the arrival times of the shock waves at each location. For this experiment that measurement was made later.
Above is a photograph of a typical deployment group. One person driving the ATV, one dropping the Texan and its geophone at the right location (marking the location if it was not already marked), and a third person that would actually place the Texan by pushing the geophone into the ground while reading off the numbers to the fourth person who would record the information.
Notice how long the shadows were getting in the photograph below. In Los Gatos Park we regrouped and stopped to attach the rest of the geophones to the remaining Texans. At this point we were over halfway finished with the deployment...but not by much.
2018-02-08