Which scale is used to measure the magnitude of earthquakes?

The measurement of earthquake magnitude is primarily done using the Moment Magnitude Scale, although the Richter Scale is also commonly referenced. The Richter Scale quantifies the amount of energy released at the earthquake's source based on the amplitude of seismic waves recorded on seismographs. This scale was developed in the 1930s and was the first widely adopted method for measuring earthquake magnitudes. However, it has limitations, particularly for large and distant earthquakes.

The Moment Magnitude Scale has become the more prevalent method for measuring larger earthquakes because it provides a more accurate assessment of the total energy released, factoring in additional parameters such as the area of the fault that slipped and the rigidity of the rock. While the Richter Scale is easy to understand and widely recognized by the public, the Moment Magnitude Scale is favored by seismologists for its precision, especially in measuring significant seismic events.

The Fujita Scale specifically measures tornado intensity, and the Beaufort Scale is used to estimate wind speed based on observed conditions. Hence, the Moment Magnitude Scale and the Richter Scale are the correct scales for measuring earthquake magnitude, but understanding the advantages of the Moment Magnitude Scale is crucial for assessing large seismic events accurately.