Physics students set up, measure tiny tremors
By Joe ReiningSeismic waves are commonly associated with earthquakes resulting in deaths of people and destruction of structures. But the study of seismic waves and their properties can have much more common and beneficial aspects, too.
On Sept. 22, students in Joe Reining’s algebra- and calculus-based physics classes at Colorado Mountain College-Spring Valley decided to make some waves. Using a portable seismograph, they were able to image and determine the depth to bedrock and map the characteristics of the material above it.
These procedures are used in the sciences and engineering to locate faults, sinkholes and other possible hazards. Chicago used similar procedures to locate pipelines where maps of their location had been lost. Archaeologists have also employed seismic information to determine the presence of buried structures.
Striking the ground with a sledge hammer, students created seismic waves which were then detected by small phone-like objects called geophones. Back at the computer lab, using tomographic software, the students were then able to construct a detailed cross section of the subsurface. This software is based on the same principles used in the medical profession to interpret ultrasounds.
As the students discovered, seismic wave studies also incorporates principles common to electricity, magnetism and geology.