The seismograph is a machine that measures the intensity of earthquakes by sensing and recording the seismic waves they generate. The seismograph displays earthquakes by graphing (writing) the seisms (earth vibrations) on a drum. At Sierra College we can determine how far away and how large the quake was. Detailed studies using many recordings allow seismologists to map the earth's interior.
Our working seismograph not only records California tremors, but also big earthquakes from elsewhere.
For the latest earthquake activity check the USGS website.