Measuring Earthquakes - 12 of 20
Measuring Earthquakes FAQs - 20 Found
Seismograms are the records (paper copy) produced by seismographs used to calculate the location and magnitude of an earthquake. They show how the ground moves with the passage of time. On a seismogram, the HORIZONTAL axis = time (measured in seconds) and the VERTICAL axis= ground displacement (usually measured in millimeters). When there is NO EQ reading there is just a straight line except for small wiggles caused by local disturbance or "noise" and the time markers.