Question

The Richter scale measures the magnitude, M, of an earthquake as a function of its intensity, I, and the intensity of a reference earthquake, .

Which equation calculates the magnitude of an earthquake with an intensity 10,000 times that of the reference earthquake?

Answer 1

Option B. M = Log 10000

Explanation:

From the question given above, we were told that the intensity (I) is 10000 times that of the reference earthquake (I₀).

Thus, we can obtain the magnitude (M) of the earthquake as follow:

Let the reference earthquake (I₀) = A

Then, the intensity (I) = 10000 × A

M = Log(I/I₀)

M = Log(10000A / A)

M = Log 10000

Thus, option B gives the right answer to the question.