In an earthshaking episode of “Built for Science“, host Tom Scott traveled to Göttingen, Germany to visit the oldest working seismic lab, where they create tiny earthquakes by dropping a four ton steel ball off of a tower that is 14 meters (46 feet) high. The information that these artificial earthquakes provide information of what’s happening beneath the ground in all directions.
Earth tremors moved through the ground in two ways the P waves or primary waves compress the ground back and forth in the direction that the wave is traveling, squeezing it together. Traveling slightly slower are the S waves the secondary waves which shear the ground side-to-side and those waves behave differently in duration and wavelength and intensity depending on the ground they’re traveling through.
