Seismometer Lab

Seismic waves are destructive, but can also be useful for seeing the layers of the Earth. One use you may not have thought about is how seismograms can be used to tell if a bomb exploded. The importance of something like this may not be obvious, but imagine there's a country that threatens to harm another country, and claims to have successfully detonated a nuclear bomb underground. You could check with a seismogram! If you would like to see a scientific article about this topic, click HERE.

Luckily seismologists can tell the difference between waves from an earthquake and waves from a bomb. This can be done using what is called a focal mechanisms plot (click HERE for a video explaining more on how to make one of these plots). In a focal mechanism plot of an earthquake, there will be four "quadrants", or areas of black and white, where each color represents the ground moving up or down. In a situation where a bomb explodes, the signal would be much different than an earthquake; the plot would be entirely black without any areas of white.

If these types of analyses interest you, perhaps your calling is in the field of seismology or structural geology! One seemingly impossible task for seismologists is to learn to predict when and where earthquakes will happen. You could be the scientist that helps to progress earthquake seismology to the next level!