Not all seismic waves are created equally and certain types of waves are created by other types of waves. For a seismic project, students can investigate the different types of waves, how they travel and how they relate to each other, then write reports and create posters or models that illustrate the different forms of seismic waves. For instance, P waves, or primary waves, are the first wave to arrive at a seismic station. These waves move fast and travel through rock or liquid by pushing and pulling on the substance through which they are traveling, much like a spring. Additionally, students can track how the arrival of primary and secondary waves help geologists locate the epicenter of earthquakes.
Because of the potential for the widespread disaster that earthquakes and seismic waves can cause, there are many different ways of monitoring seismology. One seismic project involves students investigating the different ways that geologists monitor seismic activity on the earth. Seismographs, geophones, hydrophones and accelerometers are all used to track seismic activity. Students research how each of these machines responds to seismic activity and their effectiveness at predicting earthquakes. For instance, the hydrophone is a microphone placed in water that records the movement of water caused by seismic activity. The 2011 9.0 earthquake and subsequent tsunami in Japan were recorded by a hydrophone.
A seismograph is one machine that measures and tracks changes in the earth's movement. Children can make their own seismograph as a science fair project and track movements in their home. Cut two holes in a cardboard box, then cut a hole in the bottom of a plastic cup, then one hole along the rim, and another directly across from the first. Insert a marker -- cap off -- through the hole in the bottom of the cup, then string the cup through the holes in the box. Weight the cup with rocks or marbles, then place a piece of paper underneath the marker. As you move the surface on which the box is sitting, the pen will trace squiggly lines on the paper.
In addition to helping scientists predict and locate earthquakes, seismic waves help geophysicists better understand the interior structures of the earth. Students can research and write a report on how seismic waves help to understand parts of the earth's core that are inaccessible to scientists. Additionally, students can make their own models of the earth and the earth's core and show how seismic waves released into the earth can be tracked upon their reflection and refraction.