Seismometer

A seismometer is an instrument that records earthquakes occurring anywhere on earth. Pens draw continuous lines on moving drums of paper, with a blip to mark one-minute spans. When the sensor detects an earthquake it causes the pens to jiggle and leave zigzag traces. The patterns of the traces tell us where and when the earthquake occurred. Data from this seismometer feeds into a national network of sensors to help pinpoint exact locations of earthquakes in real time.