What is a seismograph

During an earthquake, vibrations caused by the breakage of rock along the fault lines radiate outward from where the earthquake first started. The instrument used to record and measure these vibrations is called a seismograph. Normal seismographs have a part for sensing in it, called a seismometer, an amplifier, and a hardcopy display unit often using photographic or heat-sensitive paper. The visual record made by a seismograph is called a seismogram. Visually the results from a seismograph is shown in lines, if the lines have big bumps in the it means that it is a bad earthquake. If it has lttle bumps it means that it is only a little earthquake. In modern seismographs, data is stored digitally by being saved on a hardrive, disks, internet and memory sticks.