Question

If $I_0$ is the intensity of an earthquake, which of the following expressions is the correct one as per the Gutenberg and Richter for local magnitude of an earthquake?

• A. $M_L = (2/3) I_0 + 1$
• B. $M_L = (3/2) I_0 + 1$
• C. $M_L = (2/3) I_0$
• D. $M_L = (3/2) I_0$

Hint:

Gutenberg-Richter local magnitude: $M_L = (2/3) I_0 + 1$; $I_0$ is log of amplitude.

Answer 1

The Correct Option is A

The Gutenberg-Richter formula for local magnitude ($M_L$) of an earthquake relates the intensity ($I_0$) to magnitude as: $M_L = (2/3) I_0 + 1$, where $I_0$ is the logarithm of the maximum amplitude of seismic waves: - This formula adjusts for energy release and distance from the epicenter. - Other expressions do not align with the standard Gutenberg-Richter relationship.