The seismograph is a machine that measures the intensity of earthquakes by sensing and recording the seismic waves they generate. At Sierra College we can determine how far away and how large quake was.
Detailed studies using many recordings allow seismologists to map the earth's interior.
Our working seismograph not only records California tremors, but big earthquakes also. Here is a photo of the record of an 8.2 quake in Bolivia, South America that was detected here in Rocklin California. For the latest earthquake activity check the USGS website .