Seismologists use a variety of techniques to study earthquakes, including:

* Seismometers: These instruments detect and record ground motion caused by earthquakes.

* GPS: This technology can measure the movement of the Earth's crust, which can help scientists understand the build-up of stress that can lead to earthquakes.

* Geological studies: Examining the rock record can provide clues about past earthquakes and the frequency of their occurrence.

Seismology is a crucial field for understanding earthquake hazards and mitigating their effects.