Seismograph: Measuring Earthquake Waves

Seismograph Overview

• A seismograph is an instrument that measures and records the motion of the ground caused by seismic waves during an earthquake.
• The term 'seismograph' combines "seismo," meaning earthquake, and "graph," meaning to write or record.

Functionality of a Seismograph

• The seismograph consists of a mass suspended by a spring, which remains stationary while the ground shakes.
• As seismic waves pass through, the base of the seismograph moves, causing the mass to stay still and recording the movement onto a rotating drum or digital medium.

Interpretation of Seismograms

• Scientists analyze the markings on a seismogram to determine the magnitude and duration of the earthquake, as well as its depth and distance from the seismograph.
• Different types of seismic waves can be identified on the seismogram, which aids in understanding the earthquake's characteristics.

Measuring Earthquake Strength

• Scientists utilize the Richter scale or the Moment Magnitude scale (Mw) to quantify and explain the strength of earthquakes.
• The Richter scale measures the amplitude of seismic waves, while the Moment Magnitude scale accounts for the seismic moment, providing a more accurate representation of large earthquakes.