The intensity of earthquake is measured by

The correct answer is Seismograph.

Key Points

• A seismograph is an instrument used to measure and record the intensity, duration, and characteristics of earthquakes.
• The device detects and records the motion of the ground caused by seismic waves generated during an earthquake.
• Seismographs typically use a suspended mass (or pendulum) that remains stationary while the ground moves, allowing the relative motion to be recorded.
• Modern seismographs use electronic sensors and data processing systems to precisely measure and analyze seismic activities.
• Richter scale or other magnitude scales are often used alongside seismographs to quantify the strength of earthquakes.

Additional Information

• Seismic Waves: These are vibrations caused by earthquakes, volcanic eruptions, or other underground explosions. They include P-waves (primary waves), S-waves (secondary waves), and surface waves.
• Richter Scale: A logarithmic scale developed by Charles F. Richter in 1935 to measure the magnitude of earthquakes. Each increase in magnitude represents a tenfold increase in amplitude.
• Epicenter: The point on the Earth's surface directly above the origin of the earthquake (hypocenter). It is often the location of the most intense shaking.
• Mercalli Intensity Scale: A qualitative scale used to measure the effects of earthquakes based on observed damage and human perception. It ranges from I (imperceptible) to XII (total destruction).
• Seismology: The scientific study of earthquakes and the propagation of elastic waves through the Earth. It helps in understanding tectonic activities and mitigating earthquake risks.