Question

How is the magnitude of an earthquake measured, and what magnitude on the Richter scale is generally associated with the most devastating effects?

• A. At the epicenter; 5.0 and above
• B. At the source; 6.0 and above
• C. At the fault line; 7.0 and above
• D. At the surface; 4.0 and above

Answer 1

Answer:

B. At the source; 6.0 and above

The magnitude of an earthquake is measured at its source using instruments called seismographs.

• Measurement Method: Seismographs record the amplitude (size) of seismic waves generated by the earthquake. The Richter scale (and more commonly, the Moment Magnitude Scale) uses a logarithmic calculation based on these amplitudes, adjusted for distance from the epicenter.

• Devastating Effects: On the Richter scale, earthquakes registering 6.0 and above are generally associated with the most devastating effects. While even lower magnitudes can cause damage in vulnerable areas, magnitudes 6 and higher typically indicate a strong to major earthquake capable of widespread destruction.