The seismic activity of an earthquake is recorded on a seismograph.
A device used to measure the duration and magnitude of a San Francisco earthquake is an example of a seismograph.
Origin of seismographseismo- + -graph
- seis′mo·graph′ic seis′mo·graph′i·cal
data relating to the 1994 earthquake in Northridge, California
From seismo- +"Ž -graph.