This video was taken in California recently and is titled “Earthquake Testing Trucks In Action” by the person who created it:
He says: “This is going on wardlow avenue out in front of my house. I thought it was an earthquake at first and ran outside when my house started to shake.”
So why are they doing this? They are using thumper trucks and doing a seismic survey to map underground layers and structures. This video offers a nice visualization of the process:
The thumper trucks generate the sound waves. The geophones pick up the vibrations.
The thumper trucks create small earthquakes, and in many towns a small earthquake is discouraged for two reasons: 1) they are disruptive, and 2) they often precede fracking operations. This article describes a typical situation:
“They create earthquakes underground.” That’s how one official described the activity of thumper trucks, though their actual mission is to engage in seismic testing to help drilling companies understand the makeup of the various layers of materials deep underground.
Essentially, thumper trucks come equipped with a large metal foot, which stomps on the ground. The action creates seismic waves that bounce off the rocks below and are then recorded and measured by instruments on the ground. This information is then sold to drilling companies to help determine the best place to drill for gas or oil.
The Town of Tusten is holding a public hearing on September 29 to hear comments about whether the town should declare a six-month moratorium on seismic testing on the roads of Tusten.