Science Olympiad Dynamic Planet Practice Test

Which scale rates an earthquake's magnitude based on the size of seismic waves?

1. Modified Mercalli Scale

2. Richter Scale

3. Moment Magnitude Scale

4. Intense Ground Motion Scale

The correct answer is: Richter Scale

The Richter Scale is specifically designed to measure the magnitude of an earthquake based on the amplitude of seismic waves recorded by seismographs. Developed in the 1930s by Charles F. Richter, this logarithmic scale quantifies the energy released during an earthquake. As the seismic waves travel through the Earth, their size is recorded, and this data is used to calculate the earthquake's magnitude. This scale is particularly useful for quantifying smaller to medium-sized earthquakes and provides a quick and straightforward way to understand the intensity of an earthquake based on the seismic waves it produces. The values on the Richter Scale often correlate with the physical effects observed during an earthquake, making it a reliable and widely understood measurement. While other scales exist for measuring earthquakes, such as the Moment Magnitude Scale, which provides a more comprehensive assessment for larger earthquakes, the specific focus of the Richter Scale on seismic wave amplitude is what distinguishes it from the alternatives. The Modified Mercalli Scale, in contrast, rates earthquakes based on their effects and intensity rather than the magnitude derived from seismic waves.