What causes the up and down wiggles on the seismogram show above?

The up and down wiggles on a seismogram are caused by the seismic waves generated by earthquakes or other geological events. These waves travel through the Earth and are detected by seismometers, which record the vibrations as oscillations on the seismogram. The amplitude and frequency of these wiggles correspond to the intensity and type of seismic waves—primary (P) waves, secondary (S) waves, or surface waves—indicating the energy released during an event. Variations in The Wiggles can also reflect changes in the Earth's materials and structures encountered by the waves.