Skip to main content
Seismology is the study of earthquakes—how and where they originate, and how the waves they generate travel through the Earth. The primary tool of a seismologist is a seismometer, which are sensitive enough to detect even the small vibrations caused by very small—micro—earthquakes. By taking such records across a number of instruments (a ‘network’), we are able to accurately determine exactly when and where an earthquake originated. This has proven to be an exceptionally powerful tool for investigating volcanic systems and tracking how bodies of melt migrate through the subsurface in the lead up to, and during, an eruption. It is also possible to create maps of the subsurface—specifically the speeds at which seismic waves propagate through it—by comparing our observations of earthquakes to sophisticated models that incorporate information about the source and the velocity structure. One avenue for forecasting eruptions is to look for changes in the seismic data. Upticks in the number or intensity of earthquakes, evolving hypocentres, or changes to the average amplitude of vibrations at the surface, can indicate changes in the volcanic system that might indicate an impending eruption.