The earthquake waves are recorded by an instrument called:

The correct answer is Seismograph.

Key Points

•  A seismograph is an instrument used to detect and record earthquakes.
• The first seismograph was developed in 1890.
  • It consists of a mass attached to a fixed base and during an earthquake, the base moves and the mass does not.
  • The motion of the base with respect to the mass is commonly transformed into an electrical voltage.
  • The electrical voltage is recorded on paper, magnetic tape, or another recording medium.
  • This record is proportional to the motion of the seismometer mass relative to the earth, but it can be mathematically converted to a record of the absolute motion of the ground. ​

Additional Information

• Earthquake: 
  • Earthquakes are caused by seismic waves that are generated due to a sudden movement in the earth's crust. 
  • Earthquakes may occur naturally or as a result of human activities.
  • Tectonic earthquakes are generated due to the sliding of rocks along a fault plane. 
  • Volcanic earthquakes are caused due to violent volcanic eruptions.

Important Points