A seismogram is a record written by a seismograph in response to ground motions produced by an earthquake, explosion, or other ground-motion sources. Seismograms of common events are compiled to show the different seismic signals recorded by ground-shaking events. Seismograms can record everything from nearby earthquakes to earthquakes on the other side of the world, plus anything that shakes the ground near the seismograph station like people walking, elk running, rocks falling and helicopters