Simplified Seismic Records

Seismic records capture data about the energy released by earthquakes. This energy travels in the form of waves called seismic waves.
Seismic waves can be categorised into two main types: body waves (which travel through the Earth’s interior) and surface waves (which travel along the Earth’s surface).
Body waves further divide into two categories. Primary or P-waves are the fastest, moving in a push-pull (compressional) pattern. Secondary or S-waves are slower and move side-to-side or up and down, causing the most damage due to their shaking effect.
Surface waves also include two types: Love and Rayleigh waves, both of which cause ground to move in different directions leading to a great deal of destruction.
Seismometers are used to detect and record seismic waves. They produce a graphical range of waves called a seismogram. The time interval between the arrival of the P and S-waves at the seismometer helps determine the location of the earthquake’s epicentre.
Simplified seismic records help in understanding several aspects of earthquakes. These records provide information about the earthquake’s location, energy magnitude, and the Earth’s internal structure.
The study and interpretation of seismic waves fall under the domain of seismology. This knowledge helps in the prediction and preparation for future earthquakes.
Make sure to remember that not all waves move through all mediums. For example, P-waves can move through solids, liquids, and gases, but S-waves can only move through solids. This helps seismologists understand the Earth’s inner structure.
Note: when revising, take note of the differences between P-waves, S-waves, Love waves, and Rayleigh waves; their speed, direction of motion, and their effects. It’s also worthwhile to understand how seismic records are obtained and interpreted.